OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.17, a network-adjacent attacker can send a crafted SNMP response to the CUPS SNMP backend that causes an out-of-bounds read of up to 176 bytes past a stack buffer. The leaked memory is converted from UTF-16 to UTF-8 and stored as printer supply description strings, which are subsequently visible to authenticated users via IPP Get-Printer-Attributes responses and the CUPS web interface. This vulnerability is fixed in 2.4.17.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a use-after-free vulnerability exists in the CUPS scheduler (cupsd) when temporary printers are automatically deleted. cupsdDeleteTemporaryPrinters() in scheduler/printers.c calls cupsdDeletePrinter() without first expiring subscriptions that reference the printer, leaving cupsd_subscription_t.dest as a dangling pointer to freed heap memory. The dangling pointer is subsequently dereferenced at multiple code sites, causing a crash (denial of service) of the cupsd daemon. With heap grooming, this can be leveraged for code execution.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, an integer underflow vulnerability in _ppdCreateFromIPP() (cups/ppd-cache.c) allows any unprivileged local user to crash the cupsd root process by supplying a negative job-password-supported IPP attribute. The bounds check only caps the upper bound, so a negative value passes validation, is cast to size_t (wrapping to ~2^64), and is used as the length argument to memset() on a 33-byte stack buffer. This causes an immediate SIGSEGV in the cupsd root process. Combined with systemd's Restart=on-failure, an attacker can repeat the crash for sustained denial of service.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, a local unprivileged user can coerce cupsd into authenticating to an attacker-controlled localhost IPP service with a reusable Authorization: Local ... token. That token is enough to drive /admin/ requests on localhost, and the attacker can combine CUPS-Create-Local-Printer with printer-is-shared=true to persist a file:///... queue even though the normal FileDevice policy rejects such URIs. Printing to that queue gives an arbitrary root file overwrite; the PoC below uses that primitive to drop a sudoers fragment and demonstrate root command execution. At time of publication, there are no publicly available patches.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, in a network-exposed cupsd with a shared target queue, an unauthorized client can send a Print-Job to that shared PostScript queue without authentication. The server accepts a page-border value supplied as textWithoutLanguage, preserves an embedded newline through option escaping and reparse, and then reparses the resulting second-line PPD: text as a trusted scheduler control record. A follow-up raw print job can therefore make the server execute an attacker-chosen existing binary such as /usr/bin/vim as lp. At time of publication, there are no publicly available patches.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, there is a heap-based buffer overflow in the CUPS scheduler when building filter option strings from job attribute. At time of publication, there are no publicly available patches.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, the RSS notifier allows .. path traversal in notify-recipient-uri (e.g., rss:///../job.cache), letting a remote IPP client write RSS XML bytes outside CacheDir/rss (anywhere that is lp-writable). In particular, because CacheDir is group-writable by default (typically root:lp and mode 0770), the notifier (running as lp) can replace root-managed state files via temp-file + rename(). This PoC clobbers CacheDir/job.cache with RSS XML, and after restarting cupsd the scheduler fails to parse the job cache and previously queued jobs disappear. At time of publication, there are no publicly available patches.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.16 and prior, CUPS daemon (cupsd) contains an authorization bypass vulnerability due to case-insensitive username comparison during authorization checks. The vulnerability allows an unprivileged user to gain unauthorized access to restricted operations by using a user with a username that differs only in case from an authorized user. At time of publication, there are no publicly available patches.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to version 2.4.15, a user in the lpadmin group can use the cups web ui to change the config and insert a malicious line. Then the cupsd process which runs as root will parse the new config and cause an out-of-bound write. This issue has been patched in version 2.4.15.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to version 2.4.15, a client that connects to cupsd but sends slow messages, e.g. only one byte per second, delays cupsd as a whole, such that it becomes unusable by other clients. This issue has been patched in version 2.4.15.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.12 and earlier, an unsafe deserialization and validation of printer attributes causes null dereference in the libcups library. This is a remote DoS vulnerability available in local subnet in default configurations. It can cause the cups & cups-browsed to crash, on all the machines in local network who are listening for printers (so by default for all regular linux machines). On systems where the vulnerability CVE-2024-47176 (cups-filters 1.x/cups-browsed 2.x vulnerability) was not fixed, and the firewall on the machine does not reject incoming communication to IPP port, and the machine is set to be available to public internet, attack vector "Network" is possible. The current versions of CUPS and cups-browsed projects have the attack vector "Adjacent" in their default configurations. Version 2.4.13 contains a patch for CVE-2025-58364.

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.12 and earlier, when the `AuthType` is set to anything but `Basic`, if the request contains an `Authorization: Basic ...` header, the password is not checked. This results in authentication bypass. Any configuration that allows an `AuthType` that is not `Basic` is affected. Version 2.4.13 fixes the issue.