CVE-2017-3736

Public on 2018-04-26
Modified on 2018-05-10
Description
There is a carry propagating bug in the x86_64 Montgomery squaring procedure in OpenSSL before 1.0.2m and 1.1.0 before 1.1.0g. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. This only affects processors that support the BMI1, BMI2 and ADX extensions like Intel Broadwell (5th generation) and later or AMD Ryzen.
Severity
Medium
CVSS v3 Base Score
5.9
See breakdown

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 2 openssl 2018-04-26 17:38 ALAS2-2018-1004
Amazon Linux 1 openssl 2018-05-10 17:29 ALAS-2018-1016

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD CVSSv2 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N
NVD CVSSv3 6.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N