CVE-2021-32840

Name: CVE-2021-32840
Creator: NVD / NIST
Published: 2022-01-26T21:15:13.097+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.96%

Last modified Jun 17, 2026

CVE-2021-32840 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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`. EPSS estimates a 1.96% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.96%

77.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Sharpziplib Project	Sharpziplib	< 1.3.3

References

https://github.com/icsharpcode/SharpZipLib/commit/a0e96de70b5264f4c919b09253b1522bc7a221ccPatch, Third Party Advisory
https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/Exploit, Third Party Advisory
https://github.com/icsharpcode/SharpZipLib/commit/a0e96de70b5264f4c919b09253b1522bc7a221ccPatch, Third Party Advisory
https://github.com/icsharpcode/SharpZipLib/releases/tag/v1.3.3Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2021-125-sharpziplib/Exploit, Third Party Advisory

Timeline

Published: Jan 26, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32840?

How severe is CVE-2021-32840?

CVE-2021-32840 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.96% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32840?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-32840?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST