CUPS rastertopclx Filter Vulnerable to Heap Buffer Overflow Leading to Potential Arbitrary Code Execution

cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. In versions 2.0.1 and prior, a heap-buffer-overflow vulnerability in the rastertopclx filter causes the program to crash with a segmentation fault when processing maliciously crafted input data. This issue can be exploited to trigger memory corruption, potentially leading to arbitrary code execution. This issue has been patched via commit 956283c.

OpenPrinting CUPS slow client can halt cupsd, leading to a possible DoS attack

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 vulnerable to stack based out-of-bound write

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.

cups: Remote DoS via null dereference

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.

cups has Authentication bypass with AuthType Negotiate

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.

cups-browsed binds to `INADDR_ANY:631`, trusting any packet from any source

CUPS is a standards-based, open-source printing system, and `cups-browsed` contains network printing functionality including, but not limited to, auto-discovering print services and shared printers. `cups-browsed` binds to `INADDR_ANY:631`, causing it to trust any packet from any source, and can cause the `Get-Printer-Attributes` IPP request to an attacker controlled URL. When combined with other vulnerabilities, such as CVE-2024-47076, CVE-2024-47175, and CVE-2024-47177, an attacker can execute arbitrary commands remotely on the target machine without authentication when a malicious printer is printed to.

OpenPrinting CUPS/libppd Postscript Parsing Heap Overflow

Due to failure in validating the length provided by an attacker-crafted PPD PostScript document, CUPS and libppd are susceptible to a heap-based buffer overflow and possibly code execution. This issue has been fixed in CUPS version 2.4.7, released in September of 2023.

libppd's ppdCreatePPDFromIPP2 function does not sanitize IPP attributes when creating the PPD buffer

CUPS is a standards-based, open-source printing system, and `libppd` can be used for legacy PPD file support. The `libppd` function `ppdCreatePPDFromIPP2` does not sanitize IPP attributes when creating the PPD buffer. When used in combination with other functions such as `cfGetPrinterAttributes5`, can result in user controlled input and ultimately code execution via Foomatic. This vulnerability can be part of an exploit chain leading to remote code execution (RCE), as described in CVE-2024-47176.

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

CUPS is a standards-based, open-source printing system, and `libcupsfilters` contains the code of the filters of the former `cups-filters` package as library functions to be used for the data format conversion tasks needed in Printer Applications. The `cfGetPrinterAttributes5` function in `libcupsfilters` does not sanitize IPP attributes returned from an IPP server. When these IPP attributes are used, for instance, to generate a PPD file, this can lead to attacker controlled data to be provided to the rest of the CUPS system.

A stack based buffer overflow vulnerability is present in OpenPrinting ippusbxd 1.34. A specially configured printer that supports IPP-over-USB can cause a buffer overflow which can lead to a arbitrary code execution in a privileged service. To trigger the vulnerability, a malicious device would need to be connected to the vulnerable system over USB.

Cupsd Listen arbitrary chmod 0140777

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. In versions 2.4.8 and earlier, when starting the cupsd server with a Listen configuration item pointing to a symbolic link, the cupsd process can be caused to perform an arbitrary chmod of the provided argument, providing world-writable access to the target. Given that cupsd is often running as root, this can result in the change of permission of any user or system files to be world writable. Given the aforementioned Ubuntu AppArmor context, on such systems this vulnerability is limited to those files modifiable by the cupsd process. In that specific case it was found to be possible to turn the configuration of the Listen argument into full control over the cupsd.conf and cups-files.conf configuration files. By later setting the User and Group arguments in cups-files.conf, and printing with a printer configured by PPD with a `FoomaticRIPCommandLine` argument, arbitrary user and group (not root) command execution could be achieved, which can further be used on Ubuntu systems to achieve full root command execution. Commit ff1f8a623e090dee8a8aadf12a6a4b25efac143d contains a patch for the issue.

cpdb-libs vulnerable to buffer overflows via scanf

cpdb-libs provides frontend and backend libraries for the Common Printing Dialog Backends (CPDB) project. In versions 1.0 through 2.0b4, cpdb-libs is vulnerable to buffer overflows via improper use of `scanf(3)`. cpdb-libs uses the `fscanf()` and `scanf()` functions to parse command lines and configuration files, dropping the read string components into fixed-length buffers, but does not limit the length of the strings to be read by `fscanf()` and `scanf()` causing buffer overflows when a string is longer than 1023 characters. A patch for this issue is available at commit f181bd1f14757c2ae0f17cc76dc20421a40f30b7. As all buffers have a length of 1024 characters, the patch limits the maximum string length to be read to 1023 by replacing all occurrences of `%s` with `%1023s` in all calls of the `fscanf()` and `scanf()` functions.

CUPS vulnerable to use-after-free in cupsdAcceptClient()

OpenPrinting CUPS is a standards-based, open source printing system for Linux and other Unix-like operating systems. Starting in version 2.0.0 and prior to version 2.4.6, CUPS logs data of free memory to the logging service AFTER the connection has been closed, when it should have logged the data right before. This is a use-after-free bug that impacts the entire cupsd process. The exact cause of this issue is the function `httpClose(con->http)` being called in `scheduler/client.c`. The problem is that httpClose always, provided its argument is not null, frees the pointer at the end of the call, only for cupsdLogClient to pass the pointer to httpGetHostname. This issue happens in function `cupsdAcceptClient` if LogLevel is warn or higher and in two scenarios: there is a double-lookup for the IP Address (HostNameLookups Double is set in `cupsd.conf`) which fails to resolve, or if CUPS is compiled with TCP wrappers and the connection is refused by rules from `/etc/hosts.allow` and `/etc/hosts.deny`. Version 2.4.6 has a patch for this issue.

OpenPrinting CUPS vulnerable to heap buffer overflow

OpenPrinting CUPS is an open source printing system. In versions 2.4.2 and prior, a heap buffer overflow vulnerability would allow a remote attacker to launch a denial of service (DoS) attack. A buffer overflow vulnerability in the function `format_log_line` could allow remote attackers to cause a DoS on the affected system. Exploitation of the vulnerability can be triggered when the configuration file `cupsd.conf` sets the value of `loglevel `to `DEBUG`. No known patches or workarounds exist at time of publication.

cups: authorization bypass when using "local" authorization

A logic issue was addressed with improved state management. This issue is fixed in Security Update 2022-003 Catalina, macOS Monterey 12.3, macOS Big Sur 11.6.5. An application may be able to gain elevated privileges.