---
cve: "CVE-2025-59841"
severity: "CRITICAL"
cvss: 9.8
epss: "0.4%"
vendor: "FlagForgeCTF"
kev: false
exploited: false
published: "2025-09-25 16:15:35"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-09T11:39:20+01:00"
---

# CVE-2025-59841

> 9.8 CRITICAL · 🧪 PoC

## Beschreibung

Flag Forge is a Capture The Flag (CTF) platform. In versions from 2.2.0 to before 2.3.1, the FlagForge web application improperly handles session invalidation. Authenticated users can continue to access protected endpoints, such as /api/profile, even after logging out. CSRF tokens are also still valid post-logout, which can allow unauthorized actions. This issue has been patched in version 2.3.1.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2025-09-29 15:48:10
- CNA-CVSS: **9.8** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Schwachstellen-Klasse

- **CWE-384** — Session Fixation
  Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
- **CWE-613** — DEPRECATED: Insufficient Session Expiration
  This entry has been deprecated because it was insufficiently clear. Consider CWE-1462 and its descendants.

## Angriffsmuster (CAPEC)

- [CAPEC-21 — Exploitation of Trusted Identifiers](https://capec.mitre.org/data/definitions/21.html) _(Severity: High)_
- [CAPEC-31 — Accessing/Intercepting/Modifying HTTP Cookies](https://capec.mitre.org/data/definitions/31.html) _(Severity: High)_
- [CAPEC-39 — Manipulating Opaque Client-based Data Tokens](https://capec.mitre.org/data/definitions/39.html) _(Severity: Medium)_
- [CAPEC-59 — Session Credential Falsification through Prediction](https://capec.mitre.org/data/definitions/59.html) _(Severity: High)_
- [CAPEC-60 — Reusing Session IDs (aka Session Replay)](https://capec.mitre.org/data/definitions/60.html) _(Severity: High)_
- [CAPEC-61 — Session Fixation](https://capec.mitre.org/data/definitions/61.html) _(Severity: High)_
- [CAPEC-196 — Session Credential Falsification through Forging](https://capec.mitre.org/data/definitions/196.html) _(Severity: Medium)_

## ATT&CK-Techniken

- [T1134 — Access Token Manipulation](https://attack.mitre.org/techniques/T1134/)
- [T1528 — Steal Application Access Token](https://attack.mitre.org/techniques/T1528/)
- [T1539 — Steal Web Session Cookie](https://attack.mitre.org/techniques/T1539/)
- [T1134.001 — Access Token Manipulation:Token Impersonation/Theft](https://attack.mitre.org/techniques/T1134/001/)
- [T1550.004 — Use Alternate Authentication Material:Web Session Cookie](https://attack.mitre.org/techniques/T1550/004/)
- [T1134.002 — Access Token Manipulation: Create Process with Token](https://attack.mitre.org/techniques/T1134/002/)
- [T1134.003 — Access Token Manipulation: Make and Impersonate Token](https://attack.mitre.org/techniques/T1134/003/)
- [T1606 — Forge Web Credentials](https://attack.mitre.org/techniques/T1606/)

## Patch verfügbar (OSV)

- 304b6c82a4f76871b336404b91e5cdd8a7d7d5bd (Commit)

## Referenzen

- <https://github.com/FlagForgeCTF/flagForge/security/advisories/GHSA-h6pr-4cwv-6cjg>
- <https://github.com/FlagForgeCTF/flagForge/commit/304b6c82a4f76871b336404b91e5cdd8a7d7d5bd>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2025-59841/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_