CVE-2020-5221: Directory Traversal (Chroot Escape) vulnerability in uftpd

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-01-22 · updated 2026-06-17
Weakness: CWE-22

Description

In uftpd before 2.11, it is possible for an unauthenticated user to perform a directory traversal attack using multiple different FTP commands and read and write to arbitrary locations on the filesystem due to the lack of a well-written chroot jail in compose_abspath(). This has been fixed in version 2.11

Affected products

troglobit uftpd: before 2.11 — fixed in 2.11

How to fix

Upgrade to a fixed version: troglobit uftpd 2.11. Check the vendor advisory for mitigations.

References

https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fe
https://github.com/troglobit/uftpd/security/advisories/GHSA-wmx8-v7mx-6x9h
https://github.com/troglobit/uftpd/commit/455b47d3756aed162d2d0ef7f40b549f3b5b30fe
https://github.com/troglobit/uftpd/security/advisories/GHSA-wmx8-v7mx-6x9h

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