CyberSecBulletin
CVE-2022-49023NVD status: Modified

Linux: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2022-49023 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 f5c2ec288a865dbe3706b09bed12302e9f6d696b, 9e6b79a3cd17620d467311b30d56f2648f6880aa, 88a6fe3707888bd1893e9741157a7035c4159ab6 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 0.38% 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 f5c2ec288a865dbe3706b09bed12302e9f6d696b or 9e6b79a3cd17620d467311b30d56f2648f6880aa or 88a6fe3707888bd1893e9741157a7035c4159ab6 or 391cb872553627bdcf236c03ee7d5adb275e37e1, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.226 or 5.10.158 or 5.15.82 or 6.0.12, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0b8fb8235be8be99a197e8d948fc0a2df8dc261a up to, but not including, f5c2ec288a865dbe3706b09bed12302e9f6d696b; 0b8fb8235be8be99a197e8d948fc0a2df8dc261a up to, but not including, 9e6b79a3cd17620d467311b30d56f2648f6880aa; 0b8fb8235be8be99a197e8d948fc0a2df8dc261a up to, but not including, 88a6fe3707888bd1893e9741157a7035c4159ab6; 0b8fb8235be8be99a197e8d948fc0a2df8dc261a up to, but not including, 391cb872553627bdcf236c03ee7d5adb275e37e1; 0b8fb8235be8be99a197e8d948fc0a2df8dc261a up to, but not including, 9f16b5c82a025cd4c864737409234ddc44fb166a; 5.1f5c2ec288a865dbe3706b09bed12302e9f6d696b, 9e6b79a3cd17620d467311b30d56f2648f6880aa, 88a6fe3707888bd1893e9741157a7035c4159ab6, 391cb872553627bdcf236c03ee7d5adb275e37e1, 9f16b5c82a025cd4c864737409234ddc44fb166a
LinuxLinux Kernel5.1 up to, but not including, 5.4.226; 5.5 up to, but not including, 5.10.158; 5.11 up to, but not including, 5.15.82; 5.16 up to, but not including, 6.0.12; 6.15.4.226, 5.10.158, 5.15.82, 6.0.12

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 3.17.1HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: fix buffer overflow in elem comparison For vendor elements, the code here assumes that 5 octets are present without checking. Since the element itself is already checked to fit, we only need to check the length.

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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