CVE-2019-1551 | rsaz_512_sqr overflow bug on x86_64

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).

Published: 2019-12-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-1551 is rated Moderate Risk (59.8/100): CVSS Medium severity, with high exploitation likelihood (EPSS 14.30%, 96th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +11.50% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-1551

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.80% 14.30% +11.50%
2 2026-05-24 2.42% 2.80% +0.39%
3 2026-04-22 — 2.42% —

Full EPSS history (65 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-1551

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2019-1551

OS Trackers for CVE-2019-1551

vendor priority summary link
alpine medium CVE-2019-1551: 3 source package rows (openssl, openssl1.1-compat, openssl3); 30 state rows across 13 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.17-main, 3.18-community, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-community, edge-main); fixed 15, open 15. https://security.alpinelinux.org/vuln/CVE-2019-1551
debian low CVE-2019-1551 low priority: Debian including 1 source packages (openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2019-1551
gentoo normal CVE-2019-1551: 1 GLSA(s) (202004-10), 1 atom(s) (dev-libs/openssl); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-1551
redhat low — https://access.redhat.com/security/cve/CVE-2019-1551
suse medium CVE-2019-1551 severity moderate: SUSE including 460 source package names (0.1.0:libopenssl1_1-1.1.0i-14.6.1, 0.1.75:libopenssl1_1-1.1.0i-14.6.1, …), 999 product×package rows across 203 product lines (Container caasp/v4/389-ds, Container caasp/v4/busybox, … (203 product lines)): Fixed 571, Known Not Affected 271, Known Affected 157. https://www.suse.com/security/cve/CVE-2019-1551/
ubuntu low CVE-2019-1551 low priority: Ubuntu including 4 source packages (edk2, nodejs, openssl, openssl1.0), 28 status rows across 7 suites (bionic, disco, eoan, focal, trusty, upstream, xenial): not-affected 11, DNE 6, released 6, needs-triage 3, ignored 2. https://ubuntu.com/security/CVE-2019-1551

Affected software / configurations for CVE-2019-1551

Vendor Product Version Raw CPE
openssl openssl >= 1.0.2, <= 1.0.2t cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
openssl openssl >= 1.1.1, <= 1.1.1d cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.4.0.0 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*
oracle mysql_enterprise_monitor <= 4.0.12 cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*
oracle mysql_enterprise_monitor >= 8.0.0, <= 8.0.20 cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.56 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.56:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.57 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:*:*:*:*:*:*:*
oracle peoplesoft_enterprise_peopletools 8.58 cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.58:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 19.10 cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
tenable log_correlation_engine < 6.0.9 cpe:2.3:a:tenable:log_correlation_engine:*:*:*:*:*:*:*:*

References for CVE-2019-1551

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00030.html Mailing List Third Party Advisory
http://packetstormsecurity.com/files/155754/Slackware-Security-Advisory-openssl-Updates.html Third Party Advisory VDB Entry
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=419102400a2811582a7a3d4a4e317d72e5ce0a8f
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=f1c5eea8a817075d31e43f5876993c6710238c98
https://lists.debian.org/debian-lts-announce/2022/03/msg00023.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DDHOAATPWJCXRNFMJ2SASDBBNU5RJONY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EXDDAOWSAIEFQNBHWYE6PPYFV4QXGMCD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XVEP3LAK4JSPRXFO4QF4GG2IVXADV3SO/
https://seclists.org/bugtraq/2019/Dec/39 Mailing List Third Party Advisory
https://seclists.org/bugtraq/2019/Dec/46 Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202004-10 Third Party Advisory
https://security.netapp.com/advisory/ntap-20191210-0001/ Third Party Advisory
https://usn.ubuntu.com/4376-1/ Third Party Advisory
https://usn.ubuntu.com/4504-1/ Third Party Advisory
https://www.debian.org/security/2019/dsa-4594 Third Party Advisory
https://www.debian.org/security/2021/dsa-4855 Third Party Advisory
https://www.openssl.org/news/secadv/20191206.txt Vendor Advisory
https://www.oracle.com/security-alerts/cpuApr2021.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2021.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2020.html Patch Third Party Advisory
https://www.tenable.com/security/tns-2019-09 Third Party Advisory
https://www.tenable.com/security/tns-2020-03 Third Party Advisory
https://www.tenable.com/security/tns-2020-11 Third Party Advisory
https://www.tenable.com/security/tns-2021-10 Third Party Advisory
cvelogic Threat Intelligence