Related Vulnerabilities: CVE-2017-3738  

There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. 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 DH1024 are considered just feasible, 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 significant. However, for an attack on TLS to be meaningful, the server would have to share the DH1024 private key among multiple clients, which is no longer an option since CVE-2016-0701.

Severity Medium

Remote Yes

Type Private key recovery

Description

There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. 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 DH1024 are considered just feasible, 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 significant. However, for an attack on TLS to be meaningful, the server would have to share the DH1024 private key among multiple clients, which is no longer an option since CVE-2016-0701.

AVG-551 lib32-openssl 1:1.1.0.g-1 1:1.1.0.h-1 Medium Fixed

AVG-550 openssl-1.0 1.0.2.l-2 1.0.2.n-1 Medium Fixed

AVG-540 openssl 1.1.0.g-1 1.1.0.h-1 Medium Fixed

AVG-480 lib32-openssl-1.0 1.0.2.l-2 1.0.2.n-1 Medium Fixed

15 Apr 2018 ASA-201804-6 AVG-551 lib32-openssl Medium private key recovery

01 Apr 2018 ASA-201804-2 AVG-540 openssl Medium multiple issues

17 Dec 2017 ASA-201712-11 AVG-480 lib32-openssl-1.0 Medium multiple issues

https://www.openssl.org/news/vulnerabilities.html#2017-3738
https://www.openssl.org/news/secadv/20171207.txt
https://github.com/openssl/openssl/commit/5630661aecbea5fe3c4740f5fea744a1f07a6253