---
cve: "CVE-2021-29485"
severity: "CRITICAL"
cvss: 9.9
epss: "2%"
vendor: "ratpack"
kev: false
exploited: false
published: "2021-06-29 19:15:09"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-21T19:20:57+02:00"
---

# CVE-2021-29485

> 9.9 CRITICAL · 🧪 PoC

## Beschreibung

Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, a malicious attacker can achieve Remote Code Execution (RCE) via a maliciously crafted Java deserialization gadget chain leveraged against the Ratpack session store. If one's application does not use Ratpack's session mechanism, it is not vulnerable. Ratpack 1.9.0 introduces a strict allow-list mechanism that mitigates this vulnerability when used. Two possible workarounds exist. The simplest mitigation for users of earlier versions is to reduce the likelihood of attackers being able to write to the session data store. Alternatively or additionally, the allow-list mechanism could be manually back ported by providing an alternative implementation of `SessionSerializer` that uses an allow-list.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2024-08-03 22:11:05
- CNA-CVSS: **9.9** (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)

## CVSS-Vektor

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

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

## Schwachstellen-Klasse

- **CWE-502** — Deserialization of Untrusted Data
  The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

## Angriffsmuster (CAPEC)

- [CAPEC-586 — Object Injection](https://capec.mitre.org/data/definitions/586.html) _(Severity: High)_

## Patch verfügbar (OSV)

- d62e05d331577684670e793d9273bb3ddb4c7f6e (Commit)

## Referenzen

- <https://github.com/ratpack/ratpack/security/advisories/GHSA-hc33-32vw-rpp9>
- <https://mvnrepository.com/artifact/io.ratpack/ratpack-core>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2021-29485/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_