CyberSecBulletin
CVE-2022-36227NVD status: Modified

Libarchive: NULL Pointer Dereference

Published Updated By the CyberSecBulletin desk

CVE-2022-36227 is a critical-severity NULL pointer dereference vulnerability in Libarchive, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 3.6.2 as the first without the flaw, so updating Libarchive to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.46% chance of exploitation within 30 days, higher than 85% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Libarchive to 3.6.2 or a later version.
  2. Update Universal Forwarder to 8.2.12 or 9.0.6, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LibarchiveLibarchive3.0.0 up to, but not including, 3.6.23.6.2
DebianDebian Linux10.0Not stated
Fedora ProjectFedora37Not stated
SplunkUniversal Forwarder8.2.0 up to, but not including, 8.2.12; 9.0.0 up to, but not including, 9.0.6; 9.1.08.2.12, 9.0.6

Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In libarchive before 3.6.2, the software does not check for an error after calling calloc function that can return with a NULL pointer if the function fails, which leads to a resultant NULL pointer dereference. NOTE: the discoverer cites this CWE-476 remark but third parties dispute the code-execution impact: "In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution."

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

The underlying weakness: NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

How developers prevent this class of flaw

  • For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
  • Select a programming language that is not susceptible to these issues.
  • Check the results of all functions that return a value and verify that the value is non-null before acting upon it.

More NULL Pointer Dereference vulnerabilities (CWE-476)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in Libarchive

All Libarchive vulnerabilities

Recent NULL Pointer Dereference vulnerabilities

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