{"cve":"CVE-2019-1547","nvd":{"published":"2019-09-10T17:15:11.750","modified":"2026-06-17T02:28:43.530","status":"Modified","description":"Normally in OpenSSL EC groups always have a co-factor present and this is used in side channel resistant code paths. However, in some cases, it is possible to construct a group using explicit parameters (instead of using a named curve). In those cases it is possible that such a group does not have the cofactor present. This can occur even where all the parameters match a known named curve. If such a curve is used then OpenSSL falls back to non-side channel resistant code paths which may result in full key recovery during an ECDSA signature operation. In order to be vulnerable an attacker would have to have the ability to time the creation of a large number of signatures where explicit parameters with no co-factor present are in use by an application using libcrypto. For the avoidance of doubt libssl is not vulnerable because explicit parameters are never used. Fixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c). Fixed in OpenSSL 1.1.0l (Affected 1.1.0-1.1.0k). Fixed in OpenSSL 1.0.2t (Affected 1.0.2-1.0.2s).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","score":4.7},"cwes":[],"references":["http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00054.html","http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00072.html","http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00012.html","http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00016.html","http://packetstormsecurity.com/files/154467/Slackware-Security-Advisory-openssl-Updates.html"],"products":["openssl:openssl"],"source":"nvd","synced_at":"2026-10-19T20:58:39.700375520+00:00"},"epss":{"cve":"CVE-2019-1547","score":0.01163,"percentile":0.67247,"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."]}