CyberSecBulletin
CVE-2022-49952NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2022-49952 is a high-severity out-of-bounds write 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 ec186b9f4aa2e6444d5308a6cc268aada7007639, c99bc901d5eb9fbdd7bd39f625e170ce97390336, 0e33b0f322fecd7a92d9dc186535cdf97940a856 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 ec186b9f4aa2e6444d5308a6cc268aada7007639 or c99bc901d5eb9fbdd7bd39f625e170ce97390336 or 0e33b0f322fecd7a92d9dc186535cdf97940a856 or c0425c2facd9166fa083f90c9f3187ace0c7837a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.213 or 5.10.142 or 5.15.66 or 5.19.8, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxf6f9279f2bf0e37e2f1fb119d8832b8568536a04 up to, but not including, ec186b9f4aa2e6444d5308a6cc268aada7007639; f6f9279f2bf0e37e2f1fb119d8832b8568536a04 up to, but not including, c99bc901d5eb9fbdd7bd39f625e170ce97390336; f6f9279f2bf0e37e2f1fb119d8832b8568536a04 up to, but not including, 0e33b0f322fecd7a92d9dc186535cdf97940a856; f6f9279f2bf0e37e2f1fb119d8832b8568536a04 up to, but not including, c0425c2facd9166fa083f90c9f3187ace0c7837a; f6f9279f2bf0e37e2f1fb119d8832b8568536a04 up to, but not including, 9baa1415d9abdd1e08362ea2dcfadfacee8690b5; 5.1ec186b9f4aa2e6444d5308a6cc268aada7007639, c99bc901d5eb9fbdd7bd39f625e170ce97390336, 0e33b0f322fecd7a92d9dc186535cdf97940a856, c0425c2facd9166fa083f90c9f3187ace0c7837a, 9baa1415d9abdd1e08362ea2dcfadfacee8690b5
LinuxLinux Kernel5.1 up to, but not including, 5.4.213; 5.5 up to, but not including, 5.10.142; 5.11 up to, but not including, 5.15.66; 5.16 up to, but not including, 5.19.8; 6.05.4.213, 5.10.142, 5.15.66, 5.19.8

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 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: fix memory corruption on probe Add the missing sanity check on the probed-session count to avoid corrupting memory beyond the fixed-size slab-allocated session array when there are more than FASTRPC_MAX_SESSIONS sessions defined in the devicetree.

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

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended 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 Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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