---
cve: "CVE-2026-116844"
severity: "MEDIUM"
cvss: 6.3
epss: ""
vendor: "fclairamb"
kev: false
exploited: false
published: "2026-10-27 01:19:07"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-11-02T00:18:55+01:00"
---

# CVE-2026-116844

> 6.3 MEDIUM · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-10-29 10:52:21
- CNA-CVSS: **6.3** (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Schwachstellen-Klasse

- **CWE-319** — Cleartext Transmission of Sensitive Information
  The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

## Angriffsmuster (CAPEC)

- [CAPEC-65 — Sniff Application Code](https://capec.mitre.org/data/definitions/65.html) _(Severity: High)_
- [CAPEC-102 — Session Sidejacking](https://capec.mitre.org/data/definitions/102.html) _(Severity: High)_
- [CAPEC-117 — Interception](https://capec.mitre.org/data/definitions/117.html) _(Severity: Medium)_
- [CAPEC-383 — Harvesting Information via API Event Monitoring](https://capec.mitre.org/data/definitions/383.html) _(Severity: Low)_
- [CAPEC-477 — Signature Spoofing by Mixing Signed and Unsigned Content](https://capec.mitre.org/data/definitions/477.html) _(Severity: High)_

## ATT&CK-Techniken

- [T1040 — Network Sniffing](https://attack.mitre.org/techniques/T1040/)
- [T1056.004 — Input Capture: Credential API Hooking](https://attack.mitre.org/techniques/T1056/004/)

## Referenzen

- <https://github.com/fclairamb/ftpserverlib/pull/685>
- <https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/handle_misc.go#L29-L31>
- <https://github.com/fclairamb/ftpserverlib/blob/v0.32.4/client_handler.go#L720>
- <https://www.vulncheck.com/advisories/fclairamb-ftpserverlib-through-0.32.4-cleartext-ftpes-data-transfer-via-prot-p>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-116844/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_