CyberSecBulletin
CVE-2022-50368NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2022-50368 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 4e5587cddb334f7a5bb1c49ea8bbfc966fafe1b8, f649ed0e1b7a1545f8e27267d3c468b3cb222ece, 21c4679af01f1027cb559330c2e7d410089b2b36 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 0.22% 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 4e5587cddb334f7a5bb1c49ea8bbfc966fafe1b8 or f649ed0e1b7a1545f8e27267d3c468b3cb222ece or 21c4679af01f1027cb559330c2e7d410089b2b36 or 9f035d1fb30648fe70ee01627eb131c56d699b35, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.19.264 or 5.4.223 or 5.10.153 or 5.15.77, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, 4e5587cddb334f7a5bb1c49ea8bbfc966fafe1b8; a689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, f649ed0e1b7a1545f8e27267d3c468b3cb222ece; a689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, 21c4679af01f1027cb559330c2e7d410089b2b36; a689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, 9f035d1fb30648fe70ee01627eb131c56d699b35; a689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, e83b354890a3c1d5256162f87a6cc38c47ae7f20; a689554ba6ed81cf606c16539f6ffc2a1dcdaf8e up to, but not including, 2e786eb2f9cebb07e317226b60054df510b60c65; 4.14e5587cddb334f7a5bb1c49ea8bbfc966fafe1b8, f649ed0e1b7a1545f8e27267d3c468b3cb222ece, 21c4679af01f1027cb559330c2e7d410089b2b36, 9f035d1fb30648fe70ee01627eb131c56d699b35, e83b354890a3c1d5256162f87a6cc38c47ae7f20, 2e786eb2f9cebb07e317226b60054df510b60c65
LinuxLinux Kernel4.1 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; 6.14.19.264, 5.4.223, 5.10.153, 5.15.77, 6.0.7

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 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/msm/dsi: 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/502668/

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. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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