PatchTheCVECVE-2021-29479: Ratpack is a toolkit for creating web applications
CVE-2021-29479 is a high-severity flaw (CVSS 7.0) affecting ratpack. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 `Pub
Why this priority
- High severity
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.0 (High) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.9% (top 42%) |
| CISA exploited list | No |
| Weakness | CWE-807 |
| Published | 2021-06-29 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-29479?
ratpack: upgrade to 1.9.0. Exact commands for each OS are on this page.
Is CVE-2021-29479 being exploited?
CVE-2021-29479 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-29479 affect?
CVE-2021-29479 affects ratpack. Severity is high (CVSS 7.0). 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-F
How urgent is CVE-2021-29479?
Priority 49/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2021-29485 CRITICAL 9.9 UPGRADE Ratpack is a toolkit for creating web applications
- CVE-2021-29481 MEDIUM 6.5 UPGRADE Ratpack is a toolkit for creating web applications
- CVE-2021-29480 MEDIUM 4.4 UPGRADE Ratpack is a toolkit for creating web applications
- CVE-2019-10770 MEDIUM 6.1 UPGRADE All versions of io.ratpack:ratpack-core from 0.9.10 inclusive and before 1.7.6 are vulnerable to Cross-site Sc