CVE-2021-29485

9.9 CRITICAL 2% exploit odds Fix listed Code execution Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 2.0% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2021-06-29 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:47 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 2.0% in the next 30 days (EPSS).
Severity: 9.9 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-06-29 19:15 UTC
Last modified: 2026-06-17 03:47 UTC
Exploit probability: 2.0% · EPSS, next 30 days
Weakness: CWE-502 · Unsafe deserialization
Record status: Modified

Affected

Ratpack Project Ratpack < 1.9.0

Attack profile CVSS 3.1 · 9.9

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-29485.md and follow it. Check whether this project is affected by CVE-2021-29485. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record