Red Hat update for kernel-rt



Published: 2020-01-14
Risk Low
Patch available YES
Number of vulnerabilities 3
CVE-ID CVE-2018-18281
CVE-2018-20856
CVE-2019-11599
CWE-ID CWE-284
CWE-416
CWE-362
Exploitation vector Local
Public exploit Public exploit code for vulnerability #3 is available.
Vulnerable software
Subscribe
kernel-rt (Red Hat package)
Operating systems & Components / Operating system package or component

MRG Realtime
Server applications / Application servers

Vendor Red Hat Inc.

Security Bulletin

This security bulletin contains information about 3 vulnerabilities.

1) Improper access control

EUVDB-ID: #VU15643

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-18281

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a local user to bypass certain security restrictions.

The vulnerability exists due to improper access restrictions to memory when performing TLB flushes after dropping pagetable locks with mremap() syscall, A local user can access a physical page of a stale TLB entry after ftruncate() syscall is called to remove entries from the pagetables of a task that is in the middle of mremap() syscall.

Successful exploitation of the vulnerability may allow an attacker to gain access to sensitive information, stored in process memory.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 3.10.0-229.rt56.144.el6rt - 3.10.0-693.61.1.rt56.656.el6rt

MRG Realtime: 2

:

External links

http://access.redhat.com/errata/RHSA-2020:0100


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Use-after-free

EUVDB-ID: #VU19568

Risk: Low

CVSSv3.1: 3.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-20856

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local attacker to execute arbitrary code on a targeted system.

The vulnerability exists due to a use-after-free error when the "__blk_drain_queue()" function in the "block/blk-core.c" file mishandles error cases. A local authenticated attacker can access the system and execute an application that submits malicious input, cause a use-after-free memory operation error and execute arbitrary code on the targeted system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 3.10.0-229.rt56.144.el6rt - 3.10.0-693.61.1.rt56.656.el6rt

MRG Realtime: 2

:

External links

http://access.redhat.com/errata/RHSA-2020:0100


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Race condition

EUVDB-ID: #VU19996

Risk: Low

CVSSv3.1: 7.2 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2019-11599

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 with mmget_not_zero or get_task_mm calls and is related to fs/userfaultfd.c, mm/mmap.c, fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c due to kernel does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

kernel-rt (Red Hat package): 3.10.0-229.rt56.144.el6rt - 3.10.0-693.61.1.rt56.656.el6rt

MRG Realtime: 2

:

External links

http://access.redhat.com/errata/RHSA-2020:0100


Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.



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