Debian update for xen



Published: 2020-01-14
Risk Medium
Patch available YES
Number of vulnerabilities 30
CVE-ID CVE-2018-12126
CVE-2018-12127
CVE-2018-12130
CVE-2018-12207
CVE-2019-11091
CVE-2019-11135
CVE-2019-17340
CVE-2019-17341
CVE-2019-17342
CVE-2019-17343
CVE-2019-17344
CVE-2019-17345
CVE-2019-17346
CVE-2019-17347
CVE-2019-17348
CVE-2019-17349
CVE-2019-17350
CVE-2019-18420
CVE-2019-18421
CVE-2019-18422
CVE-2019-18423
CVE-2019-18424
CVE-2019-18425
CVE-2019-19577
CVE-2019-19578
CVE-2019-19579
CVE-2019-19580
CVE-2019-19581
CVE-2019-19582
CVE-2019-19583
CWE-ID CWE-200
CWE-119
CWE-399
CWE-401
CWE-362
CWE-284
CWE-264
CWE-835
CWE-20
Exploitation vector Local network
Public exploit Public exploit code for vulnerability #6 is available.
Vulnerable software
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Debian Linux
Operating systems & Components / Operating system

xen (Debian package)
Operating systems & Components / Operating system package or component

Vendor Debian

Security Bulletin

This security bulletin contains information about 30 vulnerabilities.

1) Information disclosure

EUVDB-ID: #VU28397

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2018-12126

CWE-ID: CWE-200 - Information Exposure

Exploit availability: No

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

Microarchitectural Store Buffer Data Sampling (MSBDS): Store buffers on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance_05132019.pdf

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

2) Information disclosure

EUVDB-ID: #VU28395

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2018-12127

CWE-ID: CWE-200 - Information Exposure

Exploit availability: No

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

Microarchitectural Load Port Data Sampling (MLPDS): Load ports on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance_05132019.pdf

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

3) Information disclosure

EUVDB-ID: #VU28396

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2018-12130

CWE-ID: CWE-200 - Information Exposure

Exploit availability: No

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

Microarchitectural Fill Buffer Data Sampling (MFBDS): Fill buffers on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance_05132019.pdf

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

4) Buffer overflow

EUVDB-ID: #VU22712

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2018-12207

CWE-ID: CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer

Exploit availability: No

Description

The vulnerability allows a local user to perform denial of service (DoS) attack.

The vulnerability exists due to a boundary error in the mechanism responsible for error handling on some Intel platforms. A local user of a guest operating system can use a specially crafted application to trigger memory corruption and cause the host system to stop responding.

Successful exploitation of this vulnerability may result in a denial of service (DoS) attack.

Below is the list of processor families that are affected by this vulnerability:

Client:

  • Intel Core i3 Processors
  • Intel Core i5 Processors
  • Intel Core i7 Processors
  • Intel Core m Processor Family
  • 2nd generation Intel Core Processors
  • 3rd generation Intel Core Processors
  • 4th generation Intel Core Processors
  • 5th generation Intel Core Processors
  • 6th generation Intel Core Processors
  • 7th generation Intel Core Processors
  • 8th generation Intel Core Processors
  • Intel Core X-series Processor Family
  • Intel Pentium Gold Processor Series
  • Intel Celeron Processor G Series

Server:

  • 2nd Generation Intel Xeon Scalable Processors
  • Intel Xeon Scalable Processors
  • Intel Xeon Processor E7 v4 Family
  • Intel Xeon Processor E7 v3 Family
  • Intel Xeon Processor E7 v2 Family
  • Intel Xeon Processor E7 Family
  • Intel Xeon Processor E5 v4 Family
  • Intel Xeon Processor E5 v3 Family
  • Intel Xeon Processor E5 v2 Family
  • Intel Xeon Processor E5 Family
  • Intel Xeon Processor E3 v6 Family
  • Intel Xeon Processor E3 v5 Family
  • Intel Xeon Processor E3 v4 Family
  • Intel Xeon Processor E3 v3 Family
  • Intel Xeon Processor E3 v2 Family
  • Intel Xeon Processor E3 Family
  • Intel Xeon E Processor
  • Intel Xeon D Processor
  • Intel Xeon W Processor
  • Legacy Intel Xeon Processor

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

5) Information disclosure

EUVDB-ID: #VU28398

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-11091

CWE-ID: CWE-200 - Information Exposure

Exploit availability: No

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

Microarchitectural Data Sampling Uncacheable Memory (MDSUM): Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. A list of impacted products can be found here: https://www.intel.com/content/dam/www/public/us/en/documents/corporate-information/SA00233-microcode-update-guidance_05132019.pdf

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

6) Resource management error

EUVDB-ID: #VU22704

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-11135

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition within the TSX Asynchronous Abort (TAA) in Intel CPUs. The TAA condition, on some microprocessors utilizing speculative execution, may allow an authenticated user to potentially enable information disclosure via a side channel.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

7) Memory leak

EUVDB-ID: #VU17907

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17340

CWE-ID: CWE-401 - Improper Release of Memory Before Removing Last Reference ('Memory Leak')

Exploit availability: No

Description

The vulnerability allows a local user to perform DoS attack or escalate privileges on the target system.

The vulnerability exists due memory leak when processing grant table transfer requests. A local user from one domain can gain access to data stored in memory that belong to another domain or consume all available memory resources on the system.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service attack or, in certain cases, to allow privilege escalation.


Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

8) Race condition

EUVDB-ID: #VU17906

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17341

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition when adding a passed-through PCI device to a domain after it was already started that results in the necessity to construct the IOMMU page tables on the fly therefore creating an attack window by allowing write access to the PV guests.

A local user can use a specially crafted application to perform write operations and alter such page tables without Xen auditing the changes that may result in execution of arbitrary code with hypervisor privileges.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

9) Improper access control

EUVDB-ID: #VU17905

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17342

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the host system.

The vulnerability exists due security violations within the page structure access control implementation with introduction of XENMEM_exchange hypercall. A local user can leak arbitrary amounts of memory or use a cooperating pair of PV and HVM/PVH guests to get a writable pagetable entry and escalate privileges on the host operating system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

10) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU17904

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17343

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to insecure processing of PV domains and related configuration.  An untrusted PV domain with access to a physical device can DMA into its own pagetables, leading to privilege escalation.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

11) Resource management error

EUVDB-ID: #VU17903

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17344

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to resource management error related to missing preemption in x86 PV page table unvalidation. A local user of guest operating system can use a specially crafted kernel to perform denial of service attack against the host system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

12) Resource management error

EUVDB-ID: #VU17902

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17345

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to resource management error related to page type reference counting with failed IOMMU update. A local user of guest operating system can use a specially crafted kernel to perform denial of service attack against the host system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

13) Race condition

EUVDB-ID: #VU17901

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17346

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition when processing TLB flushing on PCID-enabled guest system. A local user of guest operating system can crash a hosts system or execute arbitrary code on other guests.

Only x86 systems with at least one PCID-enabled PV guest are vulnerable.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

14) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU17900

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-17347

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the guest system.

The vulnerability exists due to incorrect implementation of the hardware supported fsgsbase feature. A local user or process on 64bit PV guest system can execute arbitrary code on the guest operating system with escalated privileges.

This vulnerability affects 64bit systems that are running on Intel IvyBridge and later hardware, and AMD Steamroller and later hardware.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

15) Resource management error

EUVDB-ID: #VU17899

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-17348

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient TLB flushing when using PCID on 64-bit x86 PV guest systems. A local user with access to guest operating system can use a specially crafted program to crash the Xen host.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

16) Infinite loop

EUVDB-ID: #VU31983

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-17349

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a LoadExcl or StoreExcl operation.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

17) Infinite loop

EUVDB-ID: #VU31984

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-17350

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

18) Input validation error

EUVDB-ID: #VU22541

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-18420

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input within the VCPUOP_initialise hypercall in Xen. A remote user on a guest operating system can run a specially crafted program and perform a denial of service attack against the host operating system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

19) Race condition

EUVDB-ID: #VU22539

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-18421

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists due to a race condition when handling restartable PV type change operations. A remote administrator of a guest operating system can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

20) Resource management error

EUVDB-ID: #VU22536

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-18422

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack or possibly escalate privileges.

The vulnerability exists due to way Xen handles exceptions on ARM systems, without changing processor level. A local user can force a critical Xen code to run with interrupts erroneously enabled during exception entry that may lead to data corruption, denial of service and potential privilege escalation.

Note, the vulnerability affects ARM systems only.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

21) Resource management error

EUVDB-ID: #VU22538

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-18423

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to the p2m_get_root_pointer() function in Xen ignores the unused top bits of a guest physical frame. A remote administrator of a guest operating system can use a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. As a result, the attacker can crash the hypervisor from the guest operating system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

22) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU22537

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-18424

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing assignment of PCI devices. A privileged user of a guest operating system can program the PCI device to directly access host memory. Once the PCI device is deassigned, the code will be written into host memory. A remote attacker can corrupt host memory and perform denial of service attack or escalate privileges on the system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

23) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU22540

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-18425

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote user to escalate privileges on the system.

The vulnerability exists due to missing descriptor table limit checking in x86 PV emulation. A remote unprivileged user of a guest operating system can escalate privileges within the same guest system.

Note, only 32-bit PV guest is affected.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

24) Input validation error

EUVDB-ID: #VU31976

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-19577

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing x86 AMD HVM guest OS users to cause a denial of service or possibly gain privileges by triggering data-structure access during pagetable-height updates. When running on AMD systems with an IOMMU, Xen attempted to dynamically adapt the number of levels of pagetables (the pagetable height) in the IOMMU according to the guest's address space size. The code to select and update the height had several bugs. Notably, the update was done without taking a lock which is necessary for safe operation. A malicious guest administrator can cause Xen to access data structures while they are being modified, causing Xen to crash.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

25) Input validation error

EUVDB-ID: #VU31978

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-19578

CWE-ID: CWE-20 - Improper Input Validation

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via degenerate chains of linear pagetables, because of an incorrect fix for CVE-2017-15595. "Linear pagetables" is a technique which involves either pointing a pagetable at itself, or to another pagetable of the same or higher level. Xen has limited support for linear pagetables: A page may either point to itself, or point to another pagetable of the same level (i.e., L2 to L2, L3 to L3, and so on). XSA-240 introduced an additional restriction that limited the "depth" of such chains by allowing pages to either *point to* other pages of the same level, or *be pointed to* by other pages of the same level, but not both. To implement this, we keep track of the number of outstanding times a page points to or is pointed to another page table, to prevent both from happening at the same time. Unfortunately, the original commit introducing this reset this count when resuming validation of a partially-validated pagetable, incorrectly dropping some "linear_pt_entry" counts. If an attacker could engineer such a situation to occur, they might be able to make loops or other arbitrary chains of linear pagetables, as described in XSA-240. A malicious or buggy PV guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Privilege escalation and information leaks cannot be excluded. All versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Only systems which have enabled linear pagetables are vulnerable. Systems which have disabled linear pagetables, either by selecting CONFIG_PV_LINEAR_PT=n when building the hypervisor, or adding pv-linear-pt=false on the command-line, are not vulnerable.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

26) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU22997

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-19579

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to an error within the PCI device assignment process that allows usage of alternative methods in Xen. A remote attacker with access to the guest OS and a physical device can gain write data into memory on the host operating system.

Successful exploitation of the vulnerability may allow a remote attacker to escalate privileges on the host operating system.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

27) Race condition

EUVDB-ID: #VU31977

Risk: Low

CVSSv3.1:

CVE-ID: CVE-2019-19580

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing, which may be difficult to exploit in practice.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

28) Resource management error

EUVDB-ID: #VU31980

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-19581

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing 32-bit Arm guest OS users to cause a denial of service (out-of-bounds access) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On 32-bit Arm accesses to bitmaps with bit a count which is a multiple of 32, an out of bounds access may occur. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. 32-bit Arm systems are vulnerable. 64-bit Arm systems are not vulnerable.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

29) Infinite loop

EUVDB-ID: #VU31981

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-19582

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing x86 guest OS users to cause a denial of service (infinite loop) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On x86 accesses to bitmaps with a compile time known size of 64 may incur undefined behavior, which may in particular result in infinite loops. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. x86 systems with 64 or more nodes are vulnerable (there might not be any such systems that Xen would run on). x86 systems with less than 64 nodes are not vulnerable.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

30) Resource management error

EUVDB-ID: #VU31979

Risk: Medium

CVSSv3.1:

CVE-ID: CVE-2019-19583

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

An issue was discovered in Xen through 4.12.x allowing x86 HVM/PVH guest OS users to cause a denial of service (guest OS crash) because VMX VMEntry checks mishandle a certain case. Please see XSA-260 for background on the MovSS shadow. Please see XSA-156 for background on the need for #DB interception. The VMX VMEntry checks do not like the exact combination of state which occurs when #DB in intercepted, Single Stepping is active, and blocked by STI/MovSS is active, despite this being a legitimate state to be in. The resulting VMEntry failure is fatal to the guest. HVM/PVH guest userspace code may be able to crash the guest, resulting in a guest Denial of Service. All versions of Xen are affected. Only systems supporting VMX hardware virtual extensions (Intel, Cyrix, or Zhaoxin CPUs) are affected. Arm and AMD systems are unaffected. Only HVM/PVH guests are affected. PV guests cannot leverage the vulnerability.

Mitigation

Update xen package to one of the following versions: 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1.

Vulnerable software versions

Debian Linux: All versions

xen (Debian package): before 4.8.5.final+shim4.10.4-1+deb9u12, 4.11.3+24-g14b62ab3e5-1~deb10u1


CPE2.3 External links

http://www.debian.org/security/2020/dsa-4602

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?



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