{"cve":"CVE-2021-28089","nvd":{"published":"2021-03-19T05:15:12.807","modified":"2026-06-17T03:45:47.593","status":"Modified","description":"Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://blog.torproject.org/node/2009","https://gitlab.torproject.org/tpo/core/tor/-/issues/40304","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HPDXB2GZHG3VNOTWSXQ3QZVHNV76WCU5/","https://security.gentoo.org/glsa/202107-25","https://blog.torproject.org/node/2009"],"products":["fedoraproject:fedora","torproject:tor"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-28089","score":0.01672,"percentile":0.76823,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}