ProFTPD before 1.3.9e and 1.3.10rc5 contains an authorization bypass in the mod_sftp copy-file extension handler that skips Limit WRITE checks for new destination files. Authenticated SFTP users can copy any readable file to a new path in write-denied directories, creating files where uploads are forbidden.
Fix
Patch, vendor advisory and mitigation references on NVD 1
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.3 · proftpd projectNVD modified 2026-10-30 11:30
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 7
- https://github.com/proftpd/proftpd/commit/b7d3de4565ae448a510feecd17b41923e44bfe16 patch
- https://github.com/proftpd/proftpd/blob/v1.3.9d/contrib/mod_sftp/fxp.c#L4748 technical-description
- https://github.com/proftpd/proftpd/releases/tag/v1.3.9e release-notes
- https://github.com/proftpd/proftpd/releases/tag/v1.3.10rc5 release-notes
- https://abraxaslabs.tech/research/proftpd-sftp-copy-file-write third-party-advisory
- https://github.com/proftpd/proftpd product
- https://www.vulncheck.com/advisories/proftpd-before-1.3-9e-and-1.3-10rc5-mod-sftp-copy-file-authorization-bypass third-party-advisory