CVE-2021-32840 Path Traversal in SharpZipLib
Attackers can extract malicious TAR files to write arbitrary files outside the target directory, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-32840?
CVE-2021-32840 is a high-severity path traversal vulnerability in icsharpcode sharpziplib, published on 26 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2021-32840?
2 open source packages ship an affected version, including SharpZipLib. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
SharpZipLib NuGet | All versions | 1.3.3 |
SharpZipLib NuGet | All versions | 1.3.3 |
Products include Sharpziplib Project Sharpziplib.
How do I fix CVE-2021-32840?
Upgrade SharpZipLib to 1.3.3 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2021-32840 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-32840 exists.
Other vulnerabilities in icsharpcode sharpziplib
Sources
Also known as GHSA-m22m-h4rf-pwq3, UBUNTU-CVE-2021-32840.