Path Traversal in Icsharpcode Sharpziplib
CVE-2021-32842
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.009 (58.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
- Icsharpcode Sharpziplib — versions 1.3.3, 1.0.0
- Sharpziplib Project
Weakness classification (CWE)
References
- securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/ (Exploit, Third Party Advisory)
- github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3 (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2021-32842?
- CVE-2021-32842 is a medium-severity vulnerability in Icsharpcode Sharpziplib, classified under Path Traversal. CVSS score: 4.0/10. Published 2022-01-26.
- How severe is CVE-2021-32842?
- Medium severity. CVSS v3 base score is 4.0 out of 10.