TI-2021-12506 Aliases CVE-2021-32841 GHSA-2x7h-96h5-rq84

Path Traversal in SharpZipLib

MEDIUM 57CWE-22Published 2022-01-26 · Updated 2025-04-22

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

SharpZipLib (or #ziplib) is a Zip, GZip, Tar and BZip2 library. Starting version 1.3.0 and prior to version 1.3.3, a check was added if the destination file is under destination directory. However, it is not enforced that `destDir` ends with slash. If the `destDir` is not slash terminated like `/home/user/dir` it is possible to create a file with a name thats begins with the destination 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 contains a patch for this vulnerability.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.01079 65th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed sharpziplib (icsharpcode): 1.3.3SharpZipLib (NuGet): 1.3.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
icsharpcode	sharpziplib	1.3.3 to before 1.3.3; 1.3.0 and later	1.3.3	Patch available	CNA
—	SharpZipLib (NuGet)	1.3.0 to before 1.3.3	1.3.3	Patch available	GHSA-2x7h-96h5-rq84

sharpziplib Vendoricsharpcode Affected 1.3.3 to before 1.3.3; 1.3.0 and later Fixed in 1.3.3 Patch available CNA
SharpZipLib (NuGet) Vendor— Affected 1.3.0 to before 1.3.3 Fixed in 1.3.3 Patch available GHSA-2x7h-96h5-rq84

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:sharpziplib_project:sharpziplib::::::::	1.3.0 to before 1.3.3	Vulnerable	icsharpcode

cpe:2.3:a:sharpziplib_project:sharpziplib:*:*:*:*:*:*:*:* Versions 1.3.0 to before 1.3.3 Vulnerable ·icsharpcode

Remediation

Fix · CNA sharpziplib (icsharpcode) Fixed in 1.3.3
Fix · GHSA-2x7h-96h5-rq84 SharpZipLib (NuGet) Fixed in 1.3.3 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2021-32841
2026-10-03 Alias added: GHSA-2x7h-96h5-rq84

References

Exploit 1

https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/

Patch 1

https://github.com/icsharpcode/SharpZipLib/commit/5c3b293de5d65b108e7f2cd0ea8f81c1b8273f78

Advisory 3

Other 1

https://github.com/icsharpcode/SharpZipLib

TI-2021-12505 Path Traversal in SharpZipLib CVSS 3.1CRITICAL 9.8
TI-2021-12507 Path Traversal in SharpZipLib CVSS 3.1MEDIUM 5.3
TI-2018-16140 Path traversal in SharpZipLib CVSS 3.1MEDIUM 5.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences