CyberSecBulletin
CVE-2024-40994NVD status: Modified

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2024-40994 is a high-severity integer overflow or wraparound 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 4b03da87d0b7074c93d9662c6e1a8939f9b8b86e, d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f, 666e934d749e50a37f3796caaf843a605f115b6f 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 4b03da87d0b7074c93d9662c6e1a8939f9b8b86e or d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f or 666e934d749e50a37f3796caaf843a605f115b6f or e1fccfb4638ee6188377867f6015d0ce35764a8e, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.15.162 or 6.1.96 or 6.6.36 or 6.9.7, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux44c494c8e30e35713c7d11ca3c5ab332cbfabacf up to, but not including, 4b03da87d0b7074c93d9662c6e1a8939f9b8b86e; 44c494c8e30e35713c7d11ca3c5ab332cbfabacf up to, but not including, d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f; 44c494c8e30e35713c7d11ca3c5ab332cbfabacf up to, but not including, 666e934d749e50a37f3796caaf843a605f115b6f; 44c494c8e30e35713c7d11ca3c5ab332cbfabacf up to, but not including, e1fccfb4638ee6188377867f6015d0ce35764a8e; 44c494c8e30e35713c7d11ca3c5ab332cbfabacf up to, but not including, 81d23d2a24012e448f651e007fac2cfd20a45ce0; 5.144b03da87d0b7074c93d9662c6e1a8939f9b8b86e, d50d62d5e6ee6aa03c00bddb91745d0b632d3b0f, 666e934d749e50a37f3796caaf843a605f115b6f, e1fccfb4638ee6188377867f6015d0ce35764a8e, 81d23d2a24012e448f651e007fac2cfd20a45ce0
LinuxLinux Kernel5.14 up to, but not including, 5.15.162; 5.16 up to, but not including, 6.1.96; 6.2 up to, but not including, 6.6.36; 6.7 up to, but not including, 6.9.7; 6.105.15.162, 6.1.96, 6.6.36, 6.9.7

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: ptp: fix integer overflow in max_vclocks_store On 32bit systems, the "4 * max" multiply can overflow. Use kcalloc() to do the allocation to prevent this.

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

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

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 Integer Overflow or Wraparound vulnerabilities

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