CVE-2023-34241

2023-06-2223:15:09

CWE-416

[email protected]

web.nvd.nist.gov

openprinting cups

use-after-free

logging service

bug

memory

linux

unix-like

version 2.0.0

version 2.4.6

httpclose

httpgethostname

cupsdacceptclient

loglevel

warn

ip address

tcp wrappers

patch

7.1 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

6.3 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

5.1%

JSON

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.