CVE-2021-39208 Information

Description

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.

CVSS Vector

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

Reference

https://github.com/adamhathcock/sharpcompress/security/advisories/GHSA-jp7f-grcv-6mjf https://github.com/adamhathcock/sharpcompress/releases/tag/0.29.0 https://github.com/adamhathcock/sharpcompress/pull/614

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

LOW

Base Score

NONE

Base Severity

4.3