CyberSecBulletin
CVE-2022-50437NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2022-50437 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions a9c1a6991a9b5aa6d0f2cbc9b8c3bf6c4d094dfa, e8f916b84e4b028ecad6c6472eaad543cc7df806, 3c43f3ec731c233eb84b66199ee76dbf3ec6ecae as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to a9c1a6991a9b5aa6d0f2cbc9b8c3bf6c4d094dfa or e8f916b84e4b028ecad6c6472eaad543cc7df806 or 3c43f3ec731c233eb84b66199ee76dbf3ec6ecae or ed7f1ff87a4afea1bc220d2ff00a7ce8e61f0b53, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.332 or 4.14.298 or 4.19.264 or 5.4.223, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, a9c1a6991a9b5aa6d0f2cbc9b8c3bf6c4d094dfa; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, e8f916b84e4b028ecad6c6472eaad543cc7df806; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, 3c43f3ec731c233eb84b66199ee76dbf3ec6ecae; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, ed7f1ff87a4afea1bc220d2ff00a7ce8e61f0b53; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, 08c7375fa27a8ceee028868e03ffb3a0db919d44; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, b48949ab451eaf1e2c04c272c8a9a96a2b56546f; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, 9efb45b45ff6254bfd1f1997a06725cb3fc998a5; a3376e3ec81c5dd0622cbc187db76d2824d31c1c up to, but not including, 4c1294da6aed1f16d47a417dcfe6602833c3c95c; and 1 more rangesa9c1a6991a9b5aa6d0f2cbc9b8c3bf6c4d094dfa, e8f916b84e4b028ecad6c6472eaad543cc7df806, 3c43f3ec731c233eb84b66199ee76dbf3ec6ecae, ed7f1ff87a4afea1bc220d2ff00a7ce8e61f0b53, 08c7375fa27a8ceee028868e03ffb3a0db919d44, b48949ab451eaf1e2c04c272c8a9a96a2b56546f
LinuxLinux Kernel3.12 up to, but not including, 4.9.332; 4.10 up to, but not including, 4.14.298; 4.15 up to, but not including, 4.19.264; 4.20 up to, but not including, 5.4.223; 5.5 up to, but not including, 5.10.153; 5.11 up to, but not including, 5.15.77; 5.16 up to, but not including, 6.0.7; 6.14.9.332, 4.14.298, 4.19.264, 5.4.223, 5.10.153, 5.15.77

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/msm/hdmi: fix memory corruption with too many bridges Add the missing sanity check on the bridge counter to avoid corrupting data beyond the fixed-sized bridge array in case there are ever more than eight bridges. Patchwork: https://patchwork.freedesktop.org/patch/502670/

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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