---
id: CVE-2019-1551
title: >-
  There is an overflow bug in the x64_64 Montgomery squaring procedure used in
  exponentiation with 512-bit moduli
summary: >-
  There is an overflow bug in the x64_64 Montgomery squaring procedure used in
  exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis
  suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as
  a res…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-190
vendor: openssl
product: openssl
affected:
  - 'openssl >= 1.0.2, <= 1.0.2t'
  - 'openssl >= 1.1.1, <= 1.1.1d'
  - leap = 15.1
  - enterprise_manager_ops_center = 12.4.0.0
  - mysql_enterprise_monitor <= 4.0.12
  - 'mysql_enterprise_monitor >= 8.0.0, <= 8.0.20'
  - peoplesoft_enterprise_peopletools = 8.56
  - peoplesoft_enterprise_peopletools = 8.57
  - peoplesoft_enterprise_peopletools = 8.58
  - ubuntu_linux = 16.04
  - ubuntu_linux = 18.04
  - ubuntu_linux = 19.10
  - fedora = 30
  - fedora = 31
  - fedora = 32
  - debian_linux = 9.0
  - debian_linux = 10.0
  - log_correlation_engine < 6.0.9
patched:
  - log_correlation_engine 6.0.9
published: '2019-12-06'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:16:51.970'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2019-1551'
references:
  - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00030.html'
    label: openssl-security@openssl.org
  - url: >-
      http://packetstormsecurity.com/files/155754/Slackware-Security-Advisory-openssl-Updates.html
    label: openssl-security@openssl.org
  - url: >-
      https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=419102400a2811582a7a3d4a4e317d72e5ce0a8f
    label: openssl-security@openssl.org
  - url: >-
      https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=f1c5eea8a817075d31e43f5876993c6710238c98
    label: openssl-security@openssl.org
  - url: 'https://lists.debian.org/debian-lts-announce/2022/03/msg00023.html'
    label: openssl-security@openssl.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/
    label: openssl-security@openssl.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/
    label: openssl-security@openssl.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/
    label: openssl-security@openssl.org
  - url: 'https://seclists.org/bugtraq/2019/Dec/39'
    label: openssl-security@openssl.org
  - url: 'https://seclists.org/bugtraq/2019/Dec/46'
    label: openssl-security@openssl.org
  - url: 'https://security.gentoo.org/glsa/202004-10'
    label: openssl-security@openssl.org
  - url: 'https://security.netapp.com/advisory/ntap-20191210-0001/'
    label: openssl-security@openssl.org
  - url: 'https://usn.ubuntu.com/4376-1/'
    label: openssl-security@openssl.org
  - url: 'https://usn.ubuntu.com/4504-1/'
    label: openssl-security@openssl.org
  - url: 'https://www.debian.org/security/2019/dsa-4594'
    label: openssl-security@openssl.org
  - url: 'https://www.debian.org/security/2021/dsa-4855'
    label: openssl-security@openssl.org
  - url: 'https://www.openssl.org/news/secadv/20191206.txt'
    label: openssl-security@openssl.org
  - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html'
    label: openssl-security@openssl.org
  - url: 'https://www.oracle.com/security-alerts/cpujan2021.html'
    label: openssl-security@openssl.org
  - url: 'https://www.oracle.com/security-alerts/cpujul2020.html'
    label: openssl-security@openssl.org
  - url: 'https://www.tenable.com/security/tns-2019-09'
    label: openssl-security@openssl.org
  - url: 'https://www.tenable.com/security/tns-2020-03'
    label: openssl-security@openssl.org
  - url: 'https://www.tenable.com/security/tns-2020-11'
    label: openssl-security@openssl.org
  - url: 'https://www.tenable.com/security/tns-2021-10'
    label: openssl-security@openssl.org
  - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00030.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      http://packetstormsecurity.com/files/155754/Slackware-Security-Advisory-openssl-Updates.html
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=419102400a2811582a7a3d4a4e317d72e5ce0a8f
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=f1c5eea8a817075d31e43f5876993c6710238c98
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2022/03/msg00023.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://seclists.org/bugtraq/2019/Dec/39'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://seclists.org/bugtraq/2019/Dec/46'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202004-10'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20191210-0001/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://usn.ubuntu.com/4376-1/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://usn.ubuntu.com/4504-1/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2019/dsa-4594'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2021/dsa-4855'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openssl.org/news/secadv/20191206.txt'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujan2021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujul2020.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.tenable.com/security/tns-2019-09'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.tenable.com/security/tns-2020-03'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.tenable.com/security/tns-2020-11'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.tenable.com/security/tns-2021-10'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2019/cve-2019-1551.json
  - url: 'https://access.redhat.com/security/cve/CVE-2019-1551'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1780995'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2019-1551'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2019-1551'
  - url: 'https://github.com/openssl/openssl/pull/10575'
  - url: 'https://access.redhat.com/errata/RHSA-2020:4384'
  - url: 'https://access.redhat.com/errata/RHSA-2020:4514'
  - url: 'https://access.redhat.com/errata/RHSA-2020:4383'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.14298
epssPercentile: 0.96585
ingestedAt: '2026-10-08T23:16:47.301Z'
scores:
  nvd: 5.3
  vendor: 4.8
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-08T21:04:33.478229Z'
---

## Overview

There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME. Fixed in OpenSSL 1.1.1e (Affected 1.1.1-1.1.1d). Fixed in OpenSSL 1.0.2u (Affected 1.0.2-1.0.2t).

## Affected

- `openssl >= 1.0.2, <= 1.0.2t`
- `openssl >= 1.1.1, <= 1.1.1d`
- `leap = 15.1`
- `enterprise_manager_ops_center = 12.4.0.0`
- `mysql_enterprise_monitor <= 4.0.12`
- `mysql_enterprise_monitor >= 8.0.0, <= 8.0.20`
- `peoplesoft_enterprise_peopletools = 8.56`
- `peoplesoft_enterprise_peopletools = 8.57`
- `peoplesoft_enterprise_peopletools = 8.58`
- `ubuntu_linux = 16.04`
- `ubuntu_linux = 18.04`
- `ubuntu_linux = 19.10`
- `fedora = 30`
- `fedora = 31`
- `fedora = 32`
- `debian_linux = 9.0`
- `debian_linux = 10.0`
- `log_correlation_engine < 6.0.9`

## Remediation

Upgrade past the affected range:

- `log_correlation_engine 6.0.9`

## Vendor advisories

- **RHSA-2020:4384** · Red Hat · fixed in: Red Hat JBoss Core Services on RHEL 6 Server, Red Hat JBoss Core Services on RHEL 7 Server · released 2020-10-28 · [advisory](https://access.redhat.com/errata/RHSA-2020:4384)
- **RHSA-2020:4514** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8) · released 2020-11-04 · [advisory](https://access.redhat.com/errata/RHSA-2020:4514)
- **RHSA-2020:4383** · Red Hat · fixed in: Red Hat JBoss Core Services · released 2020-10-28 · [advisory](https://access.redhat.com/errata/RHSA-2020:4383)
- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat JBoss Enterprise Application Platform 6, Red Hat JBoss Enterprise Web Server 2 · no fix planned: Red Hat JBoss Enterprise Application Platform 6, Red Hat JBoss Enterprise Web Server 2, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8 · updated 2026-10-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2019/cve-2019-1551.json)
