CyberSecBulletin
CVE-2024-38576NVD status: Modified

Linux: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2024-38576 is a high-severity buffer copy without checking size of input vulnerability in Linux, with a CVSS 3.1 base score of 7.0 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 e2228ed3fe7aa838fba87c79a76fb1ad9ea47138, afb39909bfb5c08111f99e21bf5be7505f59ff1c, 9351e1338539cb7f319ffc1210fa9b2aa27384b5 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 e2228ed3fe7aa838fba87c79a76fb1ad9ea47138 or afb39909bfb5c08111f99e21bf5be7505f59ff1c or 9351e1338539cb7f319ffc1210fa9b2aa27384b5 or 4c3e2ef4d8ddd313c8ce3ac30505940bea8d6257, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.93 or 6.6.33 or 6.8.12 or 6.9.3, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux245a62982502255314b63dd2c4daaedd1cd595a6 up to, but not including, e2228ed3fe7aa838fba87c79a76fb1ad9ea47138; 245a62982502255314b63dd2c4daaedd1cd595a6 up to, but not including, afb39909bfb5c08111f99e21bf5be7505f59ff1c; 245a62982502255314b63dd2c4daaedd1cd595a6 up to, but not including, 9351e1338539cb7f319ffc1210fa9b2aa27384b5; 245a62982502255314b63dd2c4daaedd1cd595a6 up to, but not including, 4c3e2ef4d8ddd313c8ce3ac30505940bea8d6257; 245a62982502255314b63dd2c4daaedd1cd595a6 up to, but not including, 3758f7d9917bd7ef0482c4184c0ad673b4c4e069; 6.0e2228ed3fe7aa838fba87c79a76fb1ad9ea47138, afb39909bfb5c08111f99e21bf5be7505f59ff1c, 9351e1338539cb7f319ffc1210fa9b2aa27384b5, 4c3e2ef4d8ddd313c8ce3ac30505940bea8d6257, 3758f7d9917bd7ef0482c4184c0ad673b4c4e069
LinuxLinux Kernel6.0 up to, but not including, 6.1.93; 6.2 up to, but not including, 6.6.33; 6.7 up to, but not including, 6.8.12; 6.9 up to, but not including, 6.9.36.1.93, 6.6.33, 6.8.12, 6.9.3

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
HighSuccess depends on conditions outside the attacker's control.
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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.0HighCNA
CVSS 3.17.1HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: rcu: Fix buffer overflow in print_cpu_stall_info() The rcuc-starvation output from print_cpu_stall_info() might overflow the buffer if there is a huge difference in jiffies difference. The situation might seem improbable, but computers sometimes get very confused about time, which can result in full-sized integers, and, in this case, buffer overflow. Also, the unsigned jiffies difference is printed using %ld, which is normally for signed integers. This is intentional for debugging purposes, but it is not obvious from the code. This commit therefore changes sprintf() to snprintf() and adds a clarifying comment about intention of %ld format. Found by Linux Verification Center (linuxtesting.org) with SVACE.

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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