{"id":"CVE-2020-13895","url":"https://www.cyber-defence.io/tools/cve/CVE-2020-13895","generatedAt":"2026-10-28T00:53:51.547Z","title":"This could conceivably have a security-relevant impact if an attacker wishes to use public r and s values when guessing whether signature verification will fail.","description":"Crypt::Perl::ECDSA in the Crypt::Perl (aka p5-Crypt-Perl) module before 0.32 for Perl fails to verify correct ECDSA signatures when r and s are small and when s = 1. This happens when using the curve secp256r1 (prime256v1). This could conceivably have a security-relevant impact if an attacker wishes to use public r and s values when guessing whether signature verification will fail.","published":"2020-06-07T01:15:11.000Z","lastModified":"2026-06-17T02:53:51.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"cwe":["CWE-347"],"affected":["p5-crypt-perl project/p5-crypt-perl"],"epss":{"score":0.00709,"percentile":0.53215,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.71%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/FGasper/p5-Crypt-Perl/commit/f960ce75502acf7404187231a706672f8369acb2","tags":["Patch","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/FGasper/p5-Crypt-Perl/issues/14","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/FGasper/p5-Crypt-Perl/commit/f960ce75502acf7404187231a706672f8369acb2","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/FGasper/p5-Crypt-Perl/issues/14","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-13895","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}