Debian Security Advisory
DLA-239-1 cups -- LTS security update
- Date Reported:
- 09 Jun 2015
- Affected Packages:
- Security database references:
- In Mitre's CVE dictionary: CVE-2015-1158, CVE-2015-1159.
- More information:
Two critical vulnerabilities have been found in the CUPS printing system:
- Improper Update of Reference Count Cupsd uses reference-counted strings with global scope. When parsing a print job request, cupsd over-decrements the reference count for a string from the request. As a result, an attacker can prematurely free an arbitrary string of global scope. They can use this to dismantle ACL’s protecting privileged operations, and upload a replacement configuration file, and subsequently run arbitrary code on a target machine.
This bug is exploitable in default configurations, and does not require any special permissions other than the basic ability to print.
- Cross-Site Scripting A cross-site scripting bug in the CUPS templating engine allows the above bug to be exploited when a user browses the web. This XSS is reachable in the default configuration for Linux instances of CUPS, and allows an attacker to bypass default configuration settings that bind the CUPS scheduler to the ‘localhost’ or loopback interface.