{"cve":"CVE-2021-31404","nvd":{"published":"2021-04-23T16:15:08.647","modified":"2026-06-17T03:51:42.963","status":"Modified","description":"Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:flow-server versions 1.0.0 through 1.0.13 (Vaadin 10.0.0 through 10.0.16), 1.1.0 prior to 2.0.0 (Vaadin 11 prior to 14), 2.0.0 through 2.4.6 (Vaadin 14.0.0 through 14.4.6), 3.0.0 prior to 5.0.0 (Vaadin 15 prior to 18), and 5.0.0 through 5.0.2 (Vaadin 18.0.0 through 18.0.5) allows attacker to guess a security token via timing attack.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","score":2.5},"cwes":["CWE-203","CWE-208"],"references":["https://github.com/vaadin/flow/pull/9875","https://vaadin.com/security/cve-2021-31404","https://github.com/vaadin/flow/pull/9875","https://vaadin.com/security/cve-2021-31404"],"products":["vaadin:flow","vaadin:vaadin"],"source":"nvd","synced_at":"2026-10-19T21:17:01.373894544+00:00"},"epss":{"cve":"CVE-2021-31404","score":0.0021,"percentile":0.11251,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-xwg3-qrcg-w9x6","url":"https://osv.dev/vulnerability/GHSA-xwg3-qrcg-w9x6","summary":"Timing side channel vulnerability in UIDL request handler in Vaadin 10, 11-14, and 15-18","modified":"2023-11-08T04:05:48.159648Z","packages":[{"ecosystem":"Maven","name":"com.vaadin:flow-server","purl":"pkg:maven/com.vaadin/flow-server","ranges":[">=1.0.0 <1.0.14"],"fixed":["1.0.14"]},{"ecosystem":"Maven","name":"com.vaadin:flow-server","purl":"pkg:maven/com.vaadin/flow-server","ranges":[">=1.1.0 <2.4.7"],"fixed":["2.4.7"]},{"ecosystem":"Maven","name":"com.vaadin:flow-server","purl":"pkg:maven/com.vaadin/flow-server","ranges":[">=3.0.0 <5.0.3"],"fixed":["5.0.3"]}]}],"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."]}