Cleartext FTP data transfers in ftpserverlib expose file contents
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-319.
Summary
Fclairamb ftpserverlib through 0.32.4 and Syncplify Server through 8.8.0 are affected. In ftpserverlib, TransferOpen checks only the transferTLS flag set by PROT, not whether the prepared data connection uses TLS (CWE-319). When a client sends PROT P after PASV or PORT, file contents and directory listings cross the network unencrypted, even when encryption is mandatory, so an on-path attacker can read or modify them.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Fclairamb ftpserverlib through 0.32.4 contains a cleartext transmission vulnerability because TransferOpen checks only the transferTLS flag set by PROT, not whether the prepared data connection uses TLS. When a client sends PROT P after PASV or PORT, file contents and directory listings cross the network unencrypted, even with mandatory encryption, letting on-path attackers read or modify them.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| fclairamb | ftpserverlib | up to 0.32.4 | — | No fix listed | CNA |
| Syncplify, Inc. | Syncplify Server! | up to 8.8.0 | — | No fix listed | CNA |
- ftpserverlib Vendorfclairamb Affected up to 0.32.4 Fixed in — No fix listed CNA
- Syncplify Server! VendorSyncplify, Inc. Affected up to 8.8.0 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for ftpserverlib. The sources list no fixed version for Syncplify Server!.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Timeline
- 2026-10-27 Threatist record created from CVE-2026-116844
- 2026-10-27 CISA SSVC decision points changed
- 2026-10-27 Priority changed: MEDIUM → LOW
- 2026-10-27 Alias added: GHSA-j2x3-vcc8-r98q
- 2026-10-29 Affected versions changed · CNA
References
Sources
- CVE-2026-116844 · CVE Program
- CVE-2026-116844 · NVD
- FIRST EPSS
- GHSA-j2x3-vcc8-r98q · GitHub Advisory Database · CC BY 4.0
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