CVE-2021-29480

What it is

Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, the client side session module uses the application startup time as the signing key by default. This means that if an attacker can determine this time, and if encryption is not also used (which is recommended, but is not on by default), the session data could be tampered with by someone with the ability to write cookies. The default configuration is unsuitable for production use as an application restart renders all sessions invalid and is not multi-host compatible, but its use is not actively prevented. As of Ratpack 1.9.0, the default value is a securely randomly generated value, generated at application startup time. As a workaround, supply an alternative signing key, as per the documentation's recommendation.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-06-29 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 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: 0.3% in the next 30 days (EPSS).
• Severity: 4.4 MEDIUM (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

0.3% · EPSS, next 30 days

Weakness

CWE-340

Record status

Modified

Affected

• Ratpack Project Ratpack < 1.9.0

Attack profile CVSS 3.1 · 4.4

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

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-2021-29480.md and follow it. Check whether this project is affected by CVE-2021-29480. 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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