Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Sharpziplib Project | Sharpziplib | >= 1.0.0, < 1.3.3 |
Related Weaknesses (CWE)
References
- https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3Release NotesThird Party Advisory
- https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/ExploitThird Party Advisory
- https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3Release NotesThird Party Advisory
- https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/ExploitThird Party Advisory
FAQ
What is CVE-2021-32842?
CVE-2021-32842 is a vulnerability with a CVSS score of 4.0 (MEDIUM). 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, ...
How severe is CVE-2021-32842?
CVE-2021-32842 has been rated MEDIUM with a CVSS base score of 4.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-32842?
Check the references section above for vendor advisories and patch information. Affected products include: Sharpziplib Project Sharpziplib.