Path Traversal in Adamhathcock Sharpcompress
CVE-2021-39208
SharpCompress is a fully managed C# library to deal with many compression types and formats. Versions prior to 0.29.0 are vulnerable to partial path traversal. SharpCompress recreates a hierarchy of directories under destinationDirectory if ExtractFullPath is set to true in options. In order to prevent extraction outside the destination directory the destinationFileName path is verified to begin with fullDestinationDirectoryPath. However, prior to version 0.29.0, it is not enforced that fullDestinationDirectoryPath ends with slash. If the destinationDirectory 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. This issue is fixed in SharpCompress version 0.29.0.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.012 (66.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
- Adamhathcock Sharpcompress — versions < 0.29.0
- Sharpcompress Project
Weakness classification (CWE)
References
- github.com/adamhathcock/sharpcompress/security/advisories/GHSA-jp7f-grcv-6mjf (Exploit, Third Party Advisory)
- github.com/adamhathcock/sharpcompress/pull/614 (Patch, Third Party Advisory)
- github.com/adamhathcock/sharpcompress/releases/tag/0.29.0 (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2021-39208?
- CVE-2021-39208 is a medium-severity vulnerability in Adamhathcock Sharpcompress, classified under Path Traversal. CVSS score: 4.3/10. Published 2021-09-16.
- How severe is CVE-2021-39208?
- Medium severity. CVSS v3 base score is 4.3 out of 10.