libcupsfilters's cfGetPrinterAttributes5 does not validate IPP attributes returned from an IPP server

The libcupsfilters library fails to validate printer information received from an IPP server, allowing an attacker to inject malicious data that gets passed to other parts of the CUPS printing system. This could lead to unauthorized access or system compromise.

The cfGetPrinterAttributes5 function in libcupsfilters does not sanitize IPP attributes from remote servers, enabling attribute injection attacks where malicious IPP responses are processed without validation and subsequently used in PPD file generation. A remote attacker controlling an IPP server can inject crafted attributes that propagate to downstream CUPS components, potentially leading to arbitrary code execution or privilege escalation depending on how the data is consumed.