NULL pointer dereference in xen (Alpine package)



Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2020-29571
CWE-ID CWE-476
Exploitation vector Network
Public exploit N/A
Vulnerable software
 IBM Systems Director
Server applications / Other server solutions

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

Vendor IBM Corporation
Alpine Linux Development Team

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) NULL pointer dereference

EUVDB-ID: #VU49140

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-29571

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems are not vulnerable.

Mitigation

Install update from vendor's website.

Vulnerable software versions

IBM Systems Director: 6.3.2.2

xen (Alpine package): 1.42

xen (Alpine package): 1.1.7-0ubuntu1 - 1.2.3-0ubuntu2.7

xen (Alpine package): 3.0.8-1 - 3.0.13-1

xen (Alpine package): 2:1.3.2-2ubuntu0.1

xen (Alpine package): 1:6.2.3-5

xen (Alpine package): 0.11-4

xen (Alpine package): 3.2.21-1

xen (Alpine package): 1.88-1

xen (Alpine package): 0.2.3.2-1

xen (Alpine package): 0.101 - 0.102ubuntu1

xen (Alpine package): 0.1.0-0ubuntu1 - 0.1.5-0ubuntu1

xen (Alpine package): 3.1-1 - 3.1-2

xen (Alpine package): 1.3.1-1 - 1.3.1-2

xen (Alpine package): 3.1-1

xen (Alpine package): 0.18.1.1-9ubuntu1

xen (Alpine package): 4.63-15

xen (Alpine package): 3.1.6.1-1

xen (Alpine package): 2.55-2 - 2.72-1

xen (Alpine package): 2.2.0.3-2ubuntu5

xen (Alpine package): 3.5.11.2003.06.04-3

xen (Alpine package): 5.4-2ubuntu1

xen (Alpine package): 5.4b-1

xen (Alpine package): 0.15

xen (Alpine package): 0.18ubuntu0.2 - 0.32

xen (Alpine package): 0.3.6.0amd12 - 1.12.9

xen (Alpine package): 1.9.9-3 - 1.9.10-1

xen (Alpine package): 0.48-4

xen (Alpine package): 0.9b-20040421-1 - 1.1-20120215-2

xen (Alpine package): 0.16 - 0.35

xen (Alpine package): 0.2 - 0.9

xen (Alpine package): 0.4

xen (Alpine package): 2.5.3 - 2.17.5ubuntu1

xen (Alpine package): 3.4.0-1

xen (Alpine package): 0.14-1 - 0.15-2

xen (Alpine package): 2014.1-3

xen (Alpine package): 24.0-0ubuntu1

xen (Alpine package): 0.5.2-0ubuntu1 - 1.2.5ubuntu1daily13.06.14-0ubuntu1

xen (Alpine package): 3.0-0ubuntu1

xen (Alpine package): 1.5.2 - 1.6.2

xen (Alpine package): 0.1.8 - 1.0.75

xen (Alpine package): 1.20.0 - 2.18.2

xen (Alpine package): 20081029ubuntu63 - 20101020ubuntu468

xen (Alpine package): 0.74 - 9.20160115ubuntu1

xen (Alpine package): 0.2.12 - 1.5.49

xen (Alpine package): 1.8.8-2ubuntu1

xen (Alpine package): 0.2.8-8 - 0.2.11-1

xen (Alpine package): 0.3 - 1.8.42

xen (Alpine package): 5.3.28-3 - 5.3.28-4

xen (Alpine package): 1.5

xen (Alpine package): 0.4.5 - 0.5.8-2.2

xen (Alpine package): 0.2.11-1build1

xen (Alpine package): 0.63

xen (Alpine package): 0.3.1-0ubuntu1 - 0.10.0-3

xen (Alpine package): 0.13-1 - 0.22.1-2

xen (Alpine package): 2.1.0-2 - 2.1.26.dfsg1-14

xen (Alpine package): 0.5.16-3.5ubuntu1 - 0.5.17-6

xen (Alpine package): 1.3-1 - 1.3-3

xen (Alpine package): 5.11-1 - 7.35.0-1

xen (Alpine package): 1.3.9-17 - 2.0.3-2

xen (Alpine package): 0.1.2-1 - 0.2.6-1ubuntu1

xen (Alpine package): 1.0.47-2 - 1.0.64-0ubuntu1

xen (Alpine package): 2.1-3-dfsg-1 - 2.1-3-dfsg-2

xen (Alpine package): 0.100-3

xen (Alpine package): 2:1.0.6-2ubuntu7 - 2:1.6.4-1

xen (Alpine package): 0.8 - 9ubuntu2

xen (Alpine package): 3.0pl1-50 - 3.0pl1-119

xen (Alpine package): 1.0.0-0ubuntu1 - 1.0.0-0ubuntu2

xen (Alpine package): expression - 7.1.1-1

xen (Alpine package): 2.8.13-7 - 2.8.13-10

xen (Alpine package): 2.4.2-16 - 2.7-1

xen (Alpine package): 0.92-0ubuntu3 - 0.98-1

xen (Alpine package): 4.5.7-1 - 8.20-3ubuntu4

xen (Alpine package): 0.2.10-3 - 0.4.6-3

xen (Alpine package): 1.5 - 1.141

xen (Alpine package): 1:0.8.6-0ubuntu4 - 1:0.9.7.6-0ubuntu2

xen (Alpine package): 0.3ubuntu7 - 0.3ubuntu15.2

xen (Alpine package): 1.2.12-1ubuntu1 - 1.2.12-1

xen (Alpine package): 0.7-svn20050721 - 1.4.29-1

xen (Alpine package): 2.8.12.1-1.6 - 3.9.0-1

xen (Alpine package): 1.0.5-2 - 1.0.8-3

xen (Alpine package): 0.25-0ubuntu1 - 0.25-0ubuntu3

xen (Alpine package): 0.9-0ubuntu1 - 0.12-0ubuntu1

xen (Alpine package): 1.4.4

xen (Alpine package): 2.2.15-1

xen (Alpine package): 1.4.2

xen (Alpine package): 4.8.9

xen (Alpine package): 3.0.4

xen (Alpine package): 2.1.0

xen (Alpine package): 1.4.17

xen (Alpine package): 2.2.0b2

xen (Alpine package): r12.0 nil

xen (Alpine package): 3.0

xen (Alpine package):

xen (Alpine package): before 4.14.1-r0

CPE2.3 External links

https://git.alpinelinux.org/aports/commit/?id=1f5fe5eb0e0bb4588f6b1b8b4e1563293acbb087


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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



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