CVE-2021-32842
Path Traversal in SharpZipLib
Description
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.
How to fix CVE-2021-32842
To remediate CVE-2021-32842, upgrade the affected package to a fixed version below.
- —upgrade to 1.3.3 or later
Is CVE-2021-32842 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 1.0.0, < 1.3.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM4.0 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |