CyberSecBulletin
CVE-2024-43852NVD status: Analyzed

Linux: Off-by-one Error

Published Updated By the CyberSecBulletin desk

CVE-2024-43852 is a high-severity off-by-one error 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 c180311c0a520692e2d0e9ca44dcd6c2ff1b41c4, 99bf7c2eccff82760fa23ce967cc67c8c219c6a6 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 0.2% 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 c180311c0a520692e2d0e9ca44dcd6c2ff1b41c4 or 99bf7c2eccff82760fa23ce967cc67c8c219c6a6, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.10.3 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux2b9ea4262ae9114b0b86ac893b4d6175d8520001 up to, but not including, c180311c0a520692e2d0e9ca44dcd6c2ff1b41c4; 2b9ea4262ae9114b0b86ac893b4d6175d8520001 up to, but not including, 99bf7c2eccff82760fa23ce967cc67c8c219c6a6; 6.7c180311c0a520692e2d0e9ca44dcd6c2ff1b41c4, 99bf7c2eccff82760fa23ce967cc67c8c219c6a6
LinuxLinux Kernel6.7 up to, but not including, 6.10.36.10.3

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: hwmon: (ltc2991) re-order conditions to fix off by one bug LTC2991_T_INT_CH_NR is 4. The st->temp_en[] array has LTC2991_MAX_CHANNEL (4) elements. Thus if "channel" is equal to LTC2991_T_INT_CH_NR then we have read one element beyond the end of the array. Flip the conditions around so that we check if "channel" is valid before using it as an array index.

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

The underlying weakness: Off-by-one Error

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

How developers prevent this class of flaw

  • When copying character arrays or using character manipulation methods, the correct size parameter must be used to account for the null terminator that needs to be added at the end of the array. Some examples of functions susceptible to this weakness in C include strcpy(), strncpy(), strcat(), strncat(), printf(), sprintf(), scanf() and sscanf().

More Off-by-one Error vulnerabilities (CWE-193)

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 Off-by-one Error vulnerabilities

Spotted an error? Tell us.