CyberSecBulletin
CVE-2024-41039NVD status: Modified

Linux: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2024-41039 is a high-severity buffer copy without checking size of input 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 fd035f0810b33c2a8792effdb82bf35920221565, 9c9877a96e033bf6c6470b3b4f06106d91ace11e, 49a79f344d0a17c6a5eef53716cc76fcdbfca9ba 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 0.29% 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 fd035f0810b33c2a8792effdb82bf35920221565 or 9c9877a96e033bf6c6470b3b4f06106d91ace11e or 49a79f344d0a17c6a5eef53716cc76fcdbfca9ba or 3019b86bce16fbb5bc1964f3544d0ce7d0137278, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.100 or 6.6.41 or 6.9.10, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf6bc909e7673c30abcbdb329e7d0aa2e83c103d7 up to, but not including, fd035f0810b33c2a8792effdb82bf35920221565; f6bc909e7673c30abcbdb329e7d0aa2e83c103d7 up to, but not including, 9c9877a96e033bf6c6470b3b4f06106d91ace11e; f6bc909e7673c30abcbdb329e7d0aa2e83c103d7 up to, but not including, 49a79f344d0a17c6a5eef53716cc76fcdbfca9ba; f6bc909e7673c30abcbdb329e7d0aa2e83c103d7 up to, but not including, 3019b86bce16fbb5bc1964f3544d0ce7d0137278; 5.16fd035f0810b33c2a8792effdb82bf35920221565, 9c9877a96e033bf6c6470b3b4f06106d91ace11e, 49a79f344d0a17c6a5eef53716cc76fcdbfca9ba, 3019b86bce16fbb5bc1964f3544d0ce7d0137278
LinuxLinux Kernel5.16 up to, but not including, 6.1.100; 6.2 up to, but not including, 6.6.41; 6.7 up to, but not including, 6.9.10; 6.106.1.100, 6.6.41, 6.9.10

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: firmware: cs_dsp: Fix overflow checking of wmfw header Fix the checking that firmware file buffer is large enough for the wmfw header, to prevent overrunning the buffer. The original code tested that the firmware data buffer contained enough bytes for the sums of the size of the structs wmfw_header + wmfw_adsp1_sizes + wmfw_footer But wmfw_adsp1_sizes is only used on ADSP1 firmware. For ADSP2 and Halo Core the equivalent struct is wmfw_adsp2_sizes, which is 4 bytes longer. So the length check didn't guarantee that there are enough bytes in the firmware buffer for a header with wmfw_adsp2_sizes. This patch splits the length check into three separate parts. Each of the wmfw_header, wmfw_adsp?_sizes and wmfw_footer are checked separately before they are used.

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

The underlying weakness: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output 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 Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)

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 Buffer Copy without Checking Size of Input vulnerabilities

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