{"cve":"CVE-2021-29480","nvd":{"published":"2021-06-29T19:15:09.340","modified":"2026-06-17T03:47:43.753","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N","score":3.1},"cwes":["CWE-330","CWE-340"],"references":["https://github.com/ratpack/ratpack/blob/29434f7ac6fd4b36a4495429b70f4c8163100332/ratpack-session/src/main/java/ratpack/session/clientside/ClientSideSessionConfig.java#L29","https://github.com/ratpack/ratpack/security/advisories/GHSA-2cc5-23r7-vc4v","https://github.com/ratpack/ratpack/blob/29434f7ac6fd4b36a4495429b70f4c8163100332/ratpack-session/src/main/java/ratpack/session/clientside/ClientSideSessionConfig.java#L29","https://github.com/ratpack/ratpack/security/advisories/GHSA-2cc5-23r7-vc4v"],"products":["ratpack_project:ratpack"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-29480","score":0.00262,"percentile":0.18071,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-2cc5-23r7-vc4v","url":"https://osv.dev/vulnerability/GHSA-2cc5-23r7-vc4v","summary":"Ratpack's default client side session signing key is highly predictable","modified":"2026-07-08T06:28:57.921466051Z","packages":[{"ecosystem":"Maven","name":"io.ratpack:ratpack-session","purl":"pkg:maven/io.ratpack/ratpack-session","ranges":["<1.9.0"],"fixed":["1.9.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}