{"id":"CVE-2018-12439","aliases":["EUVD-2018-4410","GHSA-m4cc-wf88-c8gq"],"status":"published","title":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka...","description":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.","severity":{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.00271,"percentile":0.19405,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-200"],"published":"2018-06-15T02:00:00Z","modified":"2026-06-17T01:37:47Z","products":[{"vendor":"matrixssl","product":"matrixssl"}],"references":[{"url":"https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-12439"},{"url":"https://github.com/advisories/GHSA-m4cc-wf88-c8gq"}],"sources":{"cve":[{"id":"CVE-2018-12439","description":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.","status":"published","published":"2018-06-15T02:00:00Z","modified":"2024-09-16T17:33:27.092Z","updated_at":"2026-11-02T14:35:06.679212Z"}],"euvd":[{"id":"EUVD-2018-4410","description":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.","status":"published","published":"2018-06-15T02:00:00Z","modified":"2024-09-16T17:33:27Z","updated_at":"2026-11-03T00:55:41.00036Z"}],"ghsa":[{"id":"GHSA-m4cc-wf88-c8gq","title":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka...","description":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.","status":"published","published":"2022-05-14T03:10:05Z","modified":"2023-02-02T05:07:42Z","cvss":[{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:52:33.872402Z"}],"nvd":[{"id":"CVE-2018-12439","description":"MatrixSSL through 3.9.5 Open allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.","status":"published","published":"2018-06-15T02:29:00.563Z","modified":"2026-06-17T01:37:47.35Z","cvss":[{"version":"3.0","score":4.7,"vector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":1.9,"vector":"AV:L/AC:M/Au:N/C:P/I:N/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:04:29.837913Z"}]}}