{"cve":"CVE-2020-5243","nvd":{"published":"2020-02-21T00:15:10.960","modified":"2026-06-17T03:21:07.010","status":"Modified","description":"uap-core before 0.7.3 is vulnerable to a denial of service attack when processing crafted User-Agent strings. Some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings. This has been patched in uap-core 0.7.3.","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-1333","CWE-20"],"references":["https://github.com/ua-parser/uap-core/commit/0afd61ed85396a3b5316f18bfd1edfaadf8e88e1","https://github.com/ua-parser/uap-core/security/advisories/GHSA-cmcx-xhr8-3w9p","https://github.com/ua-parser/uap-core/commit/0afd61ed85396a3b5316f18bfd1edfaadf8e88e1","https://github.com/ua-parser/uap-core/security/advisories/GHSA-cmcx-xhr8-3w9p"],"products":["uap-core_project:uap-core"],"source":"nvd","synced_at":"2026-10-19T21:02:53.949909883+00:00"},"epss":{"cve":"CVE-2020-5243","score":0.02289,"percentile":0.83203,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-cmcx-xhr8-3w9p","url":"https://osv.dev/vulnerability/GHSA-cmcx-xhr8-3w9p","summary":"Denial of Service in uap-core when processing crafted User-Agent strings","modified":"2026-07-08T06:27:49.976052814Z","packages":[{"ecosystem":"npm","name":"uap-core","purl":"pkg:npm/uap-core","ranges":["<0.7.3"],"fixed":["0.7.3"]},{"ecosystem":"RubyGems","name":"user_agent_parser","purl":"pkg:gem/user_agent_parser","ranges":["<2.6.0"],"fixed":["2.6.0"]}]}],"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."]}