CVE-2024-47175

A security issue was found in OpenPrinting CUPS. The function ppdCreatePPDFromIPP2 in the libppd library is responsible for generating a PostScript Printer Description (PPD) file based on attributes retrieved from an Internet Printing Protocol (IPP) response. Essentially, it takes printer information, usually obtained via IPP, and creates a corresponding PPD file that describes the printer’s capabilities (such as supported media sizes, resolutions, color modes, etc.). PPD files are used by printing systems like CUPS (Common Unix Printing System) to communicate with and configure printers. They provide a standardized format that allows different printers to work with the printing system in a consistent way. The ppdCreatePPDFromIPP2 function in libppd doesn’t properly check or clean IPP attributes before writing them to a temporary PPD file. This means that a remote attacker, who has control of or has hijacked an exposed printer (through UPD or mDNS), could send a harmful IPP attribute and potentially insert malicious commands into the PPD file.

Mitigation

See the security bulletin for a detailed mitigation procedure.