CVE-2024-35235

Publication date 11 June 2024

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

4.4 · Medium

Score breakdown

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.8 and earlier, when starting the cupsd server with a Listen configuration item pointing to a symbolic link, the cupsd process can be caused to perform an arbitrary chmod of the provided argument, providing world-writable access to the target. Given that cupsd is often running as root, this can result in the change of permission of any user or system files to be world writable. Given the aforementioned Ubuntu AppArmor context, on such systems this vulnerability is limited to those files modifiable by the cupsd process. In that specific case it was found to be possible to turn the configuration of the Listen argument into full control over the cupsd.conf and cups-files.conf configuration files. By later setting the User and Group arguments in cups-files.conf, and printing with a printer configured by PPD with a `FoomaticRIPCommandLine` argument, arbitrary user and group (not root) command execution could be achieved, which can further be used on Ubuntu systems to achieve full root command execution. Commit ff1f8a623e090dee8a8aadf12a6a4b25efac143d contains a patch for the issue.

Read the notes from the security team

Status

Package Ubuntu Release Status
cups 24.04 LTS noble
Fixed 2.4.7-1.2ubuntu7.1
23.10 mantic
Fixed 2.4.6-0ubuntu3.1
22.04 LTS jammy
Fixed 2.4.1op1-1ubuntu4.9
20.04 LTS focal
Fixed 2.3.1-9ubuntu1.7
18.04 LTS bionic
16.04 LTS xenial

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Notes

alexmurray

requires the attacker to be able to modify /etc/cups/cupsd.conf which NOT world-writable so requires combination with another vulnerability to be successfully exploited by an unprivileged user.

Severity score breakdown

Parameter Value
Base score 4.4 · Medium
Attack vector Local
Attack complexity Low
Privileges required High
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact None
Availability impact None
Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

Other references