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-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.

cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. In cups-filters prior to 1.28.18, by crafting a PDF file with a large `MediaBox` value, an attacker can cause CUPS-Filter 1.x’s `pdftoraster` tool to write beyond the bounds of an array. First, a PDF with a large `MediaBox` width value causes `header.cupsWidth` to become large. Next, the calculation of `bytesPerLine = (header.cupsBitsPerPixel * header.cupsWidth + 7) / 8` overflows, resulting in a small value. Then, `lineBuf` is allocated with the small `bytesPerLine` size. Finally, `convertLineChunked` calls `writePixel8`, which attempts to write to `lineBuf` outside of its buffer size (out of bounds write). In libcupsfilters, the maintainers found the same `bytesPerLine` multiplication without overflow check, but the provided test case does not cause an overflow there, because the values are different. Commit 50d94ca0f2fa6177613c97c59791bde568631865 contains a patch, which is incorporated into cups-filters version 1.28.18.

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.

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.