CUPS vulnerable to use-after-free in cupsdAcceptClient()
CVE-2023-34241

5.3MEDIUM

Key Information:

Vendor
Openprinting
Status
Cups
Vendor
CVE Published:
22 June 2023

Summary

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->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.

Affected Version(s)

cups >= 2.0.0, < 2.4.6

References

https://github.com/OpenPrinting/cups/security/advisories/...
x_refsource_CONFIRM
https://github.com/OpenPrinting/cups/commit/9809947a959e1...
x_refsource_MISC
https://github.com/OpenPrinting/cups/releases/tag/v2.4.6
x_refsource_MISC

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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CVE-2023-34241 : CUPS vulnerable to use-after-free in cupsdAcceptClient() | SecurityVulnerability.io