CVE-2026-35025
HIGHProFTPD ACL Bypass via /proc/self/root Path Prefix in RNFR
Title source: cnaDescription
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.
References (3)
Core 3
Core References
Technical Description technical-description
https://github.com/proftpd/proftpd/issues/2170
Product product
http://www.proftpd.org/
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/proftpd-acl-bypass-via-proc-self-root-path-prefix-in-rnfr
Scores
CVSS v3
8.1
EPSS
0.0035
EPSS Percentile
27.5%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-59
Status
published
Products (4)
proftpd/proftpd
1.3.10 rc1 (2 CPE variants)
proftpd/proftpd
< 1.3.9b
ProFTPD Project/ProFTPD
< 1.3.10rc2
ProFTPD Project/ProFTPD
< 1.3.9b
Published
Jun 24, 2026
Tracked Since
Jun 24, 2026