CyberSecBulletin
CVE-2024-26736NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2024-26736 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 5c27d85a69fa16a08813ba37ddfb4bbc9a1ed6b5, d9b5e2b7a8196850383c70d099bfd39e81ab6637, e56662160fc24d28cb75ac095cc6415ae1bda43e 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 0.73% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 5c27d85a69fa16a08813ba37ddfb4bbc9a1ed6b5 or d9b5e2b7a8196850383c70d099bfd39e81ab6637 or e56662160fc24d28cb75ac095cc6415ae1bda43e or e8530b170e464017203e3b8c6c49af6e916aece1, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.270 or 5.10.211 or 5.15.150 or 6.1.80, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, 5c27d85a69fa16a08813ba37ddfb4bbc9a1ed6b5; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, d9b5e2b7a8196850383c70d099bfd39e81ab6637; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, e56662160fc24d28cb75ac095cc6415ae1bda43e; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, e8530b170e464017203e3b8c6c49af6e916aece1; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, 6e6065dd25b661420fac19c34282b6c626fcd35e; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, d34a5e57632bb5ff825196ddd9a48ca403626dfa; d2ddc776a4581d900fc3bdc7803b403daae64d88 up to, but not including, 6ea38e2aeb72349cad50e38899b0ba6fbcb2af3d; 4.155c27d85a69fa16a08813ba37ddfb4bbc9a1ed6b5, d9b5e2b7a8196850383c70d099bfd39e81ab6637, e56662160fc24d28cb75ac095cc6415ae1bda43e, e8530b170e464017203e3b8c6c49af6e916aece1, 6e6065dd25b661420fac19c34282b6c626fcd35e, d34a5e57632bb5ff825196ddd9a48ca403626dfa
LinuxLinux Kernel4.15 up to, but not including, 5.4.270; 5.5 up to, but not including, 5.10.211; 5.11 up to, but not including, 5.15.150; 5.16 up to, but not including, 6.1.80; 6.2 up to, but not including, 6.6.19; 6.7 up to, but not including, 6.7.7; 6.85.4.270, 5.10.211, 5.15.150, 6.1.80, 6.6.19, 6.7.7
DebianDebian Linux10.0Not stated

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 3.18.1HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: afs: Increase buffer size in afs_update_volume_status() The max length of volume->vid value is 20 characters. So increase idbuf[] size up to 24 to avoid overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. [DH: Actually, it's 20 + NUL, so increase it to 24 and use snprintf()]

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: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

Spotted an error? Tell us.