--- id: CVE-2018-0737 title: >- The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack summary: >- The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack. An attacker with sufficient access to mount cache timing attacks during the RSA key generation process could recover the priv… severity: medium cvss: 5.9 cvssVector: 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N' cwe: - CWE-327 vendor: openssl product: openssl affected: - 'openssl >= 1.0.2b, <= 1.0.2o' - 'openssl >= 1.1.0, <= 1.1.0h' - ubuntu_linux = 14.04 - ubuntu_linux = 16.04 - ubuntu_linux = 17.10 published: '2018-04-16' updated: '2026-10-15' sourceUpdated: '2026-10-15T18:17:05.900' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2018-0737' references: - url: >- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html label: openssl-security@openssl.org - url: 'http://www.securityfocus.com/bid/103766' label: openssl-security@openssl.org - url: 'http://www.securitytracker.com/id/1040685' label: openssl-security@openssl.org - url: 'https://access.redhat.com/errata/RHSA-2018:3221' label: openssl-security@openssl.org - url: 'https://access.redhat.com/errata/RHSA-2018:3505' label: openssl-security@openssl.org - url: 'https://access.redhat.com/errata/RHSA-2019:3932' label: openssl-security@openssl.org - url: 'https://access.redhat.com/errata/RHSA-2019:3933' label: openssl-security@openssl.org - url: 'https://access.redhat.com/errata/RHSA-2019:3935' label: openssl-security@openssl.org - url: >- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=349a41da1ad88ad87825414752a8ff5fdd6a6c3f label: openssl-security@openssl.org - url: >- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=6939eab03a6e23d2bd2c3f5e34fe1d48e542e787 label: openssl-security@openssl.org - url: 'https://lists.debian.org/debian-lts-announce/2018/07/msg00043.html' label: openssl-security@openssl.org - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EWC42UXL5GHTU5G77VKBF6JYUUNGSHOM/ label: openssl-security@openssl.org - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y3IVFGSERAZLNJCK35TEM2R4726XIH3Z/ label: openssl-security@openssl.org - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZBEV5QGDRFUZDMNECFXUSN5FMYOZDE4V/ label: openssl-security@openssl.org - url: 'https://nodejs.org/en/blog/vulnerability/august-2018-security-releases/' label: openssl-security@openssl.org - url: 'https://security.gentoo.org/glsa/201811-21' label: openssl-security@openssl.org - url: 'https://security.netapp.com/advisory/ntap-20180726-0003/' label: openssl-security@openssl.org - url: 'https://securityadvisories.paloaltonetworks.com/Home/Detail/133' label: openssl-security@openssl.org - url: 'https://usn.ubuntu.com/3628-1/' label: openssl-security@openssl.org - url: 'https://usn.ubuntu.com/3628-2/' label: openssl-security@openssl.org - url: 'https://usn.ubuntu.com/3692-1/' label: openssl-security@openssl.org - url: 'https://usn.ubuntu.com/3692-2/' label: openssl-security@openssl.org - url: 'https://www.debian.org/security/2018/dsa-4348' label: openssl-security@openssl.org - url: 'https://www.debian.org/security/2018/dsa-4355' label: openssl-security@openssl.org - url: 'https://www.openssl.org/news/secadv/20180416.txt' label: openssl-security@openssl.org - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: openssl-security@openssl.org - url: 'https://www.oracle.com/security-alerts/cpuapr2020.html' label: openssl-security@openssl.org - url: >- https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html label: openssl-security@openssl.org - url: >- https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html label: openssl-security@openssl.org - url: >- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html label: openssl-security@openssl.org - url: 'https://www.tenable.com/security/tns-2018-12' label: openssl-security@openssl.org - url: 'https://www.tenable.com/security/tns-2018-13' label: openssl-security@openssl.org - url: 'https://www.tenable.com/security/tns-2018-14' label: openssl-security@openssl.org - url: 'https://www.tenable.com/security/tns-2018-17' label: openssl-security@openssl.org - url: >- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.securityfocus.com/bid/103766' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://www.securitytracker.com/id/1040685' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2018:3221' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2018:3505' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2019:3932' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2019:3933' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2019:3935' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=349a41da1ad88ad87825414752a8ff5fdd6a6c3f label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=6939eab03a6e23d2bd2c3f5e34fe1d48e542e787 label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2018/07/msg00043.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EWC42UXL5GHTU5G77VKBF6JYUUNGSHOM/ label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y3IVFGSERAZLNJCK35TEM2R4726XIH3Z/ label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZBEV5QGDRFUZDMNECFXUSN5FMYOZDE4V/ label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://nodejs.org/en/blog/vulnerability/august-2018-security-releases/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.gentoo.org/glsa/201811-21' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.netapp.com/advisory/ntap-20180726-0003/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://securityadvisories.paloaltonetworks.com/Home/Detail/133' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://usn.ubuntu.com/3628-1/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://usn.ubuntu.com/3628-2/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://usn.ubuntu.com/3692-1/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://usn.ubuntu.com/3692-2/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.debian.org/security/2018/dsa-4348' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.debian.org/security/2018/dsa-4355' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.openssl.org/news/secadv/20180416.txt' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuapr2020.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.tenable.com/security/tns-2018-12' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.tenable.com/security/tns-2018-13' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.tenable.com/security/tns-2018-14' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.tenable.com/security/tns-2018-17' label: af854a3a-2127-422b-91ae-364da2661108 tags: - nvd - cve.org ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2026-10-15T17:19:07.239978Z' epss: 0.11597 epssPercentile: 0.96018 ingestedAt: '2026-10-15T18:23:58.393Z' --- ## Overview The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack. An attacker with sufficient access to mount cache timing attacks during the RSA key generation process could recover the private key. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2b-1.0.2o). ## Affected - `openssl >= 1.0.2b, <= 1.0.2o` - `openssl >= 1.1.0, <= 1.1.0h` - `ubuntu_linux = 14.04` - `ubuntu_linux = 16.04` - `ubuntu_linux = 17.10` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges.