CVE-2017-3738

CVE-2017-3738 is an overflow bug in the AVX2 Montgomery multiplication procedure within OpenSSL versions 1.0.2-1.0.2m and 1.1.0-1.1.0g, specifically impacting processors supporting AVX2 but not ADX extensions. This vulnerability primarily affects DH1024, with attacks against RSA and DSA deemed highly improbable. Rated Medium (CVSS 5.9), an attack requires high complexity and significant resources, potentially allowing an attacker to deduce information about a private key, though a meaningful TLS attack is unlikely due to prior mitigations. There is no evidence of active exploitation, no public exploit code, and minimal community discussion, with the fix available in OpenSSL 1.0.2n and planned for 1.1.0h.