CUPS vulnerabilities

Vulnerability in CUPS printing system versions 2.4.8 and earlier. When starting the cupsd server with a Listen configuration pointing to a symbolic link, the process can perform an arbitrary chmod on the target file.

Vulnerability in the libppd library used by CUPS. The ppdCreatePPDFromIPP2 function does not sanitize IPP attributes when creating the PPD buffer, potentially leading to buffer overflow or other issues.

OpenPrinting CUPS versions 2.4.16 and earlier contain a vulnerability that allows a local unprivileged user to coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable `Authorization: Local ...` token. This token enables /admin/ requests on localhost, and the attacker can create a persistent printer queue with a file:///... URI despite the FileDevice policy. Printing to that queue allows arbitrary root file overwrite, potentially leading to privilege escalation.

OpenPrinting CUPS versions 2.4.16 and prior have a vulnerability in a network-exposed cupsd with a shared PostScript queue. An unauthenticated client can send a print job, and the server processes a page-border value with an embedded newline, allowing execution of an arbitrary binary (e.g., /usr/bin/vim) as user lp.

OpenPrinting CUPS up to version 2.4.16 has a heap-based buffer overflow in the CUPS scheduler when building filter option strings from job attributes. At the time of publication, no public patches are available.

In OpenPrinting CUPS versions 2.4.16 and prior, the RSS notifier allows path traversal in notify-recipient-uri, enabling a remote IPP client to write RSS XML bytes outside CacheDir/rss to any lp-writable location. By exploiting default group-writable permissions (root:lp, mode 0770), the notifier running as lp can overwrite root-managed state files, causing job cache parsing failures and loss of queued jobs after cupsd restart.

OpenPrinting CUPS versions 2.4.16 and prior contain an authorization bypass vulnerability due to case-insensitive username comparison. This allows an unprivileged user to gain unauthorized access to restricted operations by using a username that differs only in case from an authorized user. No public patches are available at the time of publication.