CyberSecBulletin
CVE-2023-52494NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2023-52494 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 76ed0c6f6418cec6efe6f65a0b91f84be80b72eb, 94991728c84f8df54fd9eec9b85855ef9057ea08, 2df39ac8f813860f79782807c3f7acff40b3c551 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 0.28% 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 76ed0c6f6418cec6efe6f65a0b91f84be80b72eb or 94991728c84f8df54fd9eec9b85855ef9057ea08 or 2df39ac8f813860f79782807c3f7acff40b3c551 or a9ebfc405fe1be145f414eafadcbf09506082010, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.149 or 6.1.76 or 6.6.15 or 6.7.3, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa1d2bd164c1c78f87968b7883964175ec41c32ae up to, but not including, 76ed0c6f6418cec6efe6f65a0b91f84be80b72eb; ec32332df7645e0ba463a08d483fe97665167071 up to, but not including, 94991728c84f8df54fd9eec9b85855ef9057ea08; ec32332df7645e0ba463a08d483fe97665167071 up to, but not including, 2df39ac8f813860f79782807c3f7acff40b3c551; ec32332df7645e0ba463a08d483fe97665167071 up to, but not including, a9ebfc405fe1be145f414eafadcbf09506082010; ec32332df7645e0ba463a08d483fe97665167071 up to, but not including, ecf8320111822a1ae5d5fc512953eab46d543d0b; ec32332df7645e0ba463a08d483fe97665167071 up to, but not including, eff9704f5332a13b08fbdbe0f84059c9e7051d5f; fd5f40fc887485a8b9a6806a640a0d8e0ef1afb6; 76879a980cd5ede4cb9a638999fb80d37bc09db5; and 4 more ranges76ed0c6f6418cec6efe6f65a0b91f84be80b72eb, 94991728c84f8df54fd9eec9b85855ef9057ea08, 2df39ac8f813860f79782807c3f7acff40b3c551, a9ebfc405fe1be145f414eafadcbf09506082010, ecf8320111822a1ae5d5fc512953eab46d543d0b, eff9704f5332a13b08fbdbe0f84059c9e7051d5f
LinuxLinux Kernel5.13 up to, but not including, 5.15.149; 5.16 up to, but not including, 6.1.76; 6.2 up to, but not including, 6.6.15; 6.7 up to, but not including, 6.7.35.15.149, 6.1.76, 6.6.15, 6.7.3

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: host: Add alignment check for event ring read pointer Though we do check the event ring read pointer by "is_valid_ring_ptr" to make sure it is in the buffer range, but there is another risk the pointer may be not aligned. Since we are expecting event ring elements are 128 bits(struct mhi_ring_element) aligned, an unaligned read pointer could lead to multiple issues like DoS or ring buffer memory corruption. So add a alignment check for event ring read pointer.

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

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