CyberSecBulletin
CVE-2024-50279NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2024-50279 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 4fa4feb873cea0e9d6ff883b37cca6f33169d8b4, 8501e38dc9e0060814c4085815fc83da3e6d43bf, ee1f74925717ab36f6a091104c170639501ce818 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 4fa4feb873cea0e9d6ff883b37cca6f33169d8b4 or 8501e38dc9e0060814c4085815fc83da3e6d43bf or ee1f74925717ab36f6a091104c170639501ce818 or ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.19.324 or 5.4.286 or 5.10.230 or 5.15.172, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, 4fa4feb873cea0e9d6ff883b37cca6f33169d8b4; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, 8501e38dc9e0060814c4085815fc83da3e6d43bf; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, ee1f74925717ab36f6a091104c170639501ce818; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, 56507203e1b6127967ec2b51fb0b23a0d4af1334; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, e57648ce325fa405fe6bbd0e6a618ced7c301a2d; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, 3b02c40ff10fdf83cc545850db208de855ebe22c; f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 up to, but not including, 792227719725497ce10a8039803bec13f89f8910; and 1 more ranges4fa4feb873cea0e9d6ff883b37cca6f33169d8b4, 8501e38dc9e0060814c4085815fc83da3e6d43bf, ee1f74925717ab36f6a091104c170639501ce818, ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f, 56507203e1b6127967ec2b51fb0b23a0d4af1334, e57648ce325fa405fe6bbd0e6a618ced7c301a2d
LinuxLinux Kernel3.13 up to, but not including, 4.19.324; 4.20 up to, but not including, 5.4.286; 5.5 up to, but not including, 5.10.230; 5.11 up to, but not including, 5.15.172; 5.16 up to, but not including, 6.1.117; 6.2 up to, but not including, 6.6.61; 6.7 up to, but not including, 6.11.8; 6.124.19.324, 5.4.286, 5.10.230, 5.15.172, 6.1.117, 6.6.61

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
NoneNothing can be modified.
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:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.1HighNVD
CVSS 3.17.1HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: dm cache: fix out-of-bounds access to the dirty bitset when resizing dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access. Reproduce steps: 1. create a cache device of 1024 cache blocks (128 bytes dirty bitset) dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80) dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache KASAN reports: BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131 (...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0 (...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 Fix by making the index post-incremented.

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

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

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 Read vulnerabilities

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