Severity Medium
Remote Yes
Type Information disclosure
A carry propagation bug has been found in OpenSSL < 1.1.0g in the x86_64 Montgomery squaring procedure. 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.
Group Package Affected Fixed Severity Status Ticket
AVG-480 lib32-openssl-1.0 1.0.2.l-2 1.0.2.n-1 Medium Fixed
AVG-479 openssl-1.0 1.0.2.l-1 1.0.2.n-1 Medium Fixed
AVG-478 lib32-openssl 1:1.1.0.f-1 1:1.1.0.g-1 Medium Fixed
AVG-477 openssl 1.1.0.f-2 1.1.0.g-1 Medium Fixed
Date Advisory Group Package Severity Description
16 Dec 2017 ASA-201712-9 AVG-479 openssl-1.0 Medium multiple issues
17 Dec 2017 ASA-201712-11 AVG-480 lib32-openssl-1.0 Medium multiple issues
08 Nov 2017 ASA-201711-15 AVG-478 lib32-openssl Medium multiple issues
07 Nov 2017 ASA-201711-14 AVG-477 openssl Medium multiple issues