Description
ProFTPD through 1.3.9b and 1.3.10rc2 contains an access control bypass vulnerability that allows authenticated FTP users to circumvent Directory ACL restrictions by prefixing paths with /proc/self/root in the RNFR command handler. Attackers can exploit the unresolved symlink components in dir_canonical_path() to cause dir_check() to perform lexical path comparisons that match no configured Directory block, enabling rename operations on files in DenyAll-protected directories and subsequent retrieval of those files. Mitigation: Sessions configured with DefaultRoot (chroot) are not affected, as chroot changes the directory to which /proc/self/root resolves.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| ProFTPD Project | ProFTPD | <= 1.3.9b; <= 1.3.10rc2 |
References
- http://www.proftpd.org/Product, Release Notes
- https://github.com/proftpd/proftpd/issues/2170Issue Tracking, Mitigation
- https://www.vulncheck.com/advisories/proftpd-acl-bypass-via-proc-self-root-path-prefix-in-rnfrThird Party Advisory
Timeline
- Published
- Jun 24, 2026
- Last modified
- Oct 25, 2026
- NVD status
- Analyzed