CVE-2019-1551: Canonical Ubuntu Linux

Medium severity, CVSS 5.3. EPSS: 14.3% chance of exploitation in the next 30 days.

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 products

• Canonical Ubuntu Linux: version 16.04 only; version 18.04 only; version 19.10 only
• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 30 only; version 31 only; version 32 only
• OpenSSL OpenSSL: from 1.0.2, up to and including 1.0.2t; from 1.1.1, up to and including 1.1.1d
• Opensuse Leap: version 15.1 only
• Oracle Enterprise Manager Ops Center: version 12.4.0.0 only
• Oracle MySQL Enterprise Monitor: up to and including 4.0.12; from 8.0.0, up to and including 8.0.20
• Oracle PeopleSoft Enterprise PeopleTools: version 8.56 only; version 8.57 only; version 8.58 only
• Tenable Log Correlation Engine: before 6.0.9 (fixed in 6.0.9)

Published 2019-12-06. Last modified 2026-10-08.