Use After Free Affecting cups package, versions <2.4.2-3+deb12u1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.05% (20th percentile)

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  • Snyk IDSNYK-DEBIAN12-CUPS-5734094
  • published23 Jun 2023
  • disclosed22 Jun 2023

Introduced: 22 Jun 2023

CVE-2023-34241  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Debian:12 cups to version 2.4.2-3+deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream cups package and not the cups package as distributed by Debian. See How to fix? for Debian:12 relevant fixed versions and status.

OpenPrinting CUPS is a standards-based, open source printing system for Linux and other Unix-like operating systems. Starting in version 2.0.0 and prior to version 2.4.6, CUPS logs data of free memory to the logging service AFTER the connection has been closed, when it should have logged the data right before. This is a use-after-free bug that impacts the entire cupsd process.

The exact cause of this issue is the function httpClose(con-&gt;http) being called in scheduler/client.c. The problem is that httpClose always, provided its argument is not null, frees the pointer at the end of the call, only for cupsdLogClient to pass the pointer to httpGetHostname. This issue happens in function cupsdAcceptClient if LogLevel is warn or higher and in two scenarios: there is a double-lookup for the IP Address (HostNameLookups Double is set in cupsd.conf) which fails to resolve, or if CUPS is compiled with TCP wrappers and the connection is refused by rules from /etc/hosts.allow and /etc/hosts.deny.

Version 2.4.6 has a patch for this issue.

CVSS Scores

version 3.1