What’s Vulnerable › Vulnerabilities

CVE-2021-32840: Path Traversal in SharpZipLib

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-01-26 · updated 2026-06-17
• Weakness: CWE-22

Description

SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Prior to version 1.3.3, a TAR file entry `../evil.txt` may be extracted in the parent directory of `destFolder`. This leads to arbitrary file write that may lead to code execution. The vulnerability was patched in version 1.3.3.

Affected products

• icsharpcode sharpziplib: before 1.3.3 — fixed in 1.3.3

How to fix

Upgrade to a fixed version: icsharpcode sharpziplib 1.3.3. Check the vendor advisory for mitigations.

References

• https://github.com/icsharpcode/SharpZipLib/commit/a0e96de70b5264f4c919b09253b1522bc7a221cc
• https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3
• https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/
• https://github.com/icsharpcode/SharpZipLib/commit/a0e96de70b5264f4c919b09253b1522bc7a221cc
• https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3
• https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/

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