CyberSecBulletin
CVE-2024-40902NVD status: Modified

Linux: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2024-40902 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 f0dedb5c511ed82cbaff4997a8decf2351ba549f, 1e84c9b1838152a87cf453270a5fa75c5037e83a, fc745f6e83cb650f9a5f2c864158e3a5ea76dad0 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 0.32% 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 f0dedb5c511ed82cbaff4997a8decf2351ba549f or 1e84c9b1838152a87cf453270a5fa75c5037e83a or fc745f6e83cb650f9a5f2c864158e3a5ea76dad0 or 480e5bc21f2c42d90c2c16045d64d824dcdd5ec7, whichever matches your release line, or a later version.
  2. Update linux_kernel to f0dedb5c511e or 1e84c9b18381 or fc745f6e83cb or 480e5bc21f2c, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, f0dedb5c511ed82cbaff4997a8decf2351ba549f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 1e84c9b1838152a87cf453270a5fa75c5037e83a; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, fc745f6e83cb650f9a5f2c864158e3a5ea76dad0; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 480e5bc21f2c42d90c2c16045d64d824dcdd5ec7; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 33aecc5799c93d3ee02f853cb94e201f9731f123; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 4598233d9748fe4db4e13b9f473588aa25e87d69; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, b537cb2f4c4a1357479716a9c339c0bda03d873f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 7c55b78818cfb732680c4a72ab270cc2d2ee3d0f; and 1 more rangesf0dedb5c511ed82cbaff4997a8decf2351ba549f, 1e84c9b1838152a87cf453270a5fa75c5037e83a, fc745f6e83cb650f9a5f2c864158e3a5ea76dad0, 480e5bc21f2c42d90c2c16045d64d824dcdd5ec7, 33aecc5799c93d3ee02f853cb94e201f9731f123, 4598233d9748fe4db4e13b9f473588aa25e87d69
Linuxlinux_kernel1da177e4c3f4 up to, but not including, f0dedb5c511e; 1da177e4c3f4 up to, but not including, 1e84c9b18381; 1da177e4c3f4 up to, but not including, fc745f6e83cb; 1da177e4c3f4 up to, but not including, 480e5bc21f2c; 1da177e4c3f4 up to, but not including, 33aecc5799c9; 1da177e4c3f4 up to, but not including, 4598233d9748; 1da177e4c3f4 up to, but not including, b537cb2f4c4a; 1da177e4c3f4 up to, but not including, 7c55b78818cff0dedb5c511e, 1e84c9b18381, fc745f6e83cb, 480e5bc21f2c, 33aecc5799c9, 4598233d9748

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 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: jfs: xattr: fix buffer overflow for invalid xattr When an xattr size is not what is expected, it is printed out to the kernel log in hex format as a form of debugging. But when that xattr size is bigger than the expected size, printing it out can cause an access off the end of the buffer. Fix this all up by properly restricting the size of the debug hex dump in the kernel log.

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: total).
  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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