Loop with Unreachable Exit Condition ('Infinite Loop') in pdfio

Vulnerability Description

PDFio is a simple C library for reading and writing PDF files. There is a denial of service (DOS) vulnerability in the TTF parser. Maliciously crafted TTF files can cause the program to utilize 100% of the Memory and enter an infinite loop. This can also lead to a heap-buffer-overflow vulnerability. An infinite loop occurs in the read_camp function by nGroups value. The ttf.h library is vulnerable. A value called nGroups is extracted from the file, and by changing that value, you can cause the program to utilize 100% of the Memory and enter an infinite loop. If the value of nGroups in the file is small, an infinite loop will not occur. This library, whether used as a standalone binary or as part of another application, is vulnerable to DOS attacks when parsing certain types of files. Automated systems, including web servers that use this code to convert PDF submissions into plaintext, can be DOSed if an attacker uploads a malicious TTF file. This issue has been addressed in release version 1.3.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.

References

• https://github.com/michaelrsweet/pdfio/security/advisories/GHSA-4hh9-j68x-8353
• https://github.com/michaelrsweet/pdfio/commit/e4e1c39578279386b0ab9f9ac14b20a8bad4f935