CVE-2021-29479
HIGHDescription
Ratpack is a toolkit for creating web applications. In versions prior to 1.9.0, a user supplied `X-Forwarded-Host` header can be used to perform cache poisoning of a cache fronting a Ratpack server if the cache key does not include the `X-Forwarded-Host` header as a cache key. Users are only vulnerable if they do not configure a custom `PublicAddress` instance. For versions prior to 1.9.0, by default, Ratpack utilizes an inferring version of `PublicAddress` which is vulnerable. This can be used to perform redirect cache poisoning where an attacker can force a cached redirect to redirect to their site instead of the intended redirect location. The vulnerability was patched in Ratpack 1.9.0. As a workaround, ensure that `ServerConfigBuilder::publicAddress` correctly configures the server in production.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L
Exploit Intelligence
Moderate risk: more likely to be exploited than 55% of all known CVEs.
References
Related Vulnerabilities
Other CWE-807 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2026-34486 | High | 7.5 | 81% | KEV | Fix |
| CVE-2026-21509 | High | 7.8 | 72% | KEV | Fix |
| CVE-2024-13974 | High | 8.1 | 6.7% | - | Fix |
| CVE-2021-41129 | High | 8.1 | 1.8% | - | Fix |
| CVE-2026-21514 | High | 7.8 | 1.5% | KEV | - |
| CVE-2025-49827 | Critical | 9.8 | 1.4% | - | Fix |
Common questions
How do I fix CVE-2021-29479?
Upgrade ratpack to 1.9.0 or later.
Is CVE-2021-29479 being actively exploited?
Not that we know of. CVE-2021-29479 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.86% is the estimated probability that it will be exploited in the next 30 days. That is higher than 55% of all scored CVEs.
How severe is CVE-2021-29479?
CVE-2021-29479 has a CVSS v3 base score of 7.0, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-29479 affect?
Published advisories record a fix for ratpack (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2021-29479
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.