CVE-2021-32842: Sharpziplib Project Sharpziplib

Medium severity, CVSS 5.3. EPSS: 0.9% chance of exploitation in the next 30 days.

SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Starting version 1.0.0 and prior to version 1.3.3, a check was added if the destination file is under a destination directory. However, it is not enforced that `_baseDirectory` ends with slash. If the _baseDirectory is not slash terminated like `/home/user/dir` it is possible to create a file with a name thats begins as the destination directory one level up from the directory, i.e. `/home/user/dir.sh`. Because of the file name and destination directory constraints, the arbitrary file creation impact is limited and depends on the use case. Version 1.3.3 fixed this vulnerability.

Affected products

• Sharpziplib Project Sharpziplib: from 1.0.0, before 1.3.3 (fixed in 1.3.3)

Published 2022-01-26. Last modified 2026-06-17.