CyberSecBulletin
CVE-2023-52755NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2023-52755 is a critical-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions aaf0a07d60887d6c36fc46a24de0083744f07819, 8387c94d73ec66eb597c7a23a8d9eadf64bfbafa, 09d9d8b40a3338193619c14ed4dc040f4f119e70 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 28.1% chance of exploitation within 30 days, which is in the top 1.86% of all scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to aaf0a07d60887d6c36fc46a24de0083744f07819 or 8387c94d73ec66eb597c7a23a8d9eadf64bfbafa or 09d9d8b40a3338193619c14ed4dc040f4f119e70 or 712e01f32e577e7e48ab0adb5fe550646a3d93cb, whichever matches your release line, or a later version.
  2. Update linux_kernel to aaf0a07d6088 or 8387c94d73ec or 09d9d8b40a33 or 712e01f32e57, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, aaf0a07d60887d6c36fc46a24de0083744f07819; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 8387c94d73ec66eb597c7a23a8d9eadf64bfbafa; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 09d9d8b40a3338193619c14ed4dc040f4f119e70; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 712e01f32e577e7e48ab0adb5fe550646a3d93cb; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, eebff19acaa35820cb09ce2ccb3d21bee2156ffb; 5.15aaf0a07d60887d6c36fc46a24de0083744f07819, 8387c94d73ec66eb597c7a23a8d9eadf64bfbafa, 09d9d8b40a3338193619c14ed4dc040f4f119e70, 712e01f32e577e7e48ab0adb5fe550646a3d93cb, eebff19acaa35820cb09ce2ccb3d21bee2156ffb
Linuxlinux_kernel1da177e4c3f4 up to, but not including, aaf0a07d6088; 1da177e4c3f4 up to, but not including, 8387c94d73ec; 1da177e4c3f4 up to, but not including, 09d9d8b40a33; 1da177e4c3f4 up to, but not including, 712e01f32e57; 1da177e4c3f4 up to, but not including, eebff19acaa3aaf0a07d6088, 8387c94d73ec, 09d9d8b40a33, 712e01f32e57, eebff19acaa3

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalCNA
CVSS 3.18.4HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab out of bounds write in smb_inherit_dacl() slab out-of-bounds write is caused by that offsets is bigger than pntsd allocation size. This patch add the check to validate 3 offsets using allocation size.

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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