CyberSecBulletin
CVE-2023-52804NVD status: Modified

Linux: Improper Validation of Array Index

Published Updated By the CyberSecBulletin desk

CVE-2023-52804 is a high-severity improper validation of array index 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 a0649e2dd4a3595b5595a29d0064d047c2fae2fb, ce15b0f1a431168f07b1cc6c9f71206a2db5c809, 32bd8f1cbcf8b663e29dd1f908ba3a129541a11b 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 0.26% 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 a0649e2dd4a3595b5595a29d0064d047c2fae2fb or ce15b0f1a431168f07b1cc6c9f71206a2db5c809 or 32bd8f1cbcf8b663e29dd1f908ba3a129541a11b or c6c8863fb3f57700ab583d875adda04caaf2278a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.14.331 or 4.19.300 or 5.4.262 or 5.10.202, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, a0649e2dd4a3595b5595a29d0064d047c2fae2fb; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, ce15b0f1a431168f07b1cc6c9f71206a2db5c809; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 32bd8f1cbcf8b663e29dd1f908ba3a129541a11b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, c6c8863fb3f57700ab583d875adda04caaf2278a; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 1f74d336990f37703a8eee77153463d65b67f70e; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5013f8269887642cca784adc8db9b5f0b771533f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, dca403bb035a565bb98ecc1dda5d30f676feda40; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 2323de34a3ae61a9f9b544c18583f71cea86721f; and 2 more rangesa0649e2dd4a3595b5595a29d0064d047c2fae2fb, ce15b0f1a431168f07b1cc6c9f71206a2db5c809, 32bd8f1cbcf8b663e29dd1f908ba3a129541a11b, c6c8863fb3f57700ab583d875adda04caaf2278a, 1f74d336990f37703a8eee77153463d65b67f70e, 5013f8269887642cca784adc8db9b5f0b771533f
LinuxLinux Kernelbefore 4.14.331; 4.15 up to, but not including, 4.19.300; 4.20 up to, but not including, 5.4.262; 5.5 up to, but not including, 5.10.202; 5.11 up to, but not including, 5.15.140; 5.16 up to, but not including, 6.1.64; 6.2 up to, but not including, 6.5.13; 6.6 up to, but not including, 6.6.34.14.331, 4.19.300, 5.4.262, 5.10.202, 5.15.140, 6.1.64

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: fs/jfs: Add validity check for db_maxag and db_agpref Both db_maxag and db_agpref are used as the index of the db_agfree array, but there is currently no validity check for db_maxag and db_agpref, which can lead to errors. The following is related bug reported by Syzbot: UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:639:20 index 7936 is out of range for type 'atomic_t[128]' Add checking that the values of db_maxag and db_agpref are valid indexes for the db_agfree array.

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

The underlying weakness: Improper Validation of Array Index

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How developers prevent this class of flaw

  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
  • Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.

More Improper Validation of Array Index vulnerabilities (CWE-129)

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 Improper Validation of Array Index vulnerabilities

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