OpenSSL CVE-2017-3732 Information Disclosure Vulnerability
by CIRT Team
Description: There is a carry propagating bug 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. For example this can occur by default in OpenSSL DHE based SSL/TLS ciphersuites. Note: This issue is very similar to CVE-2015-3193 but must be treated as a separate problem. Reported by OSS-Fuzz project.
An attacker can exploit this issue to gain access to sensitive information that may aid in further attacks. Versions prior to OpenSSL 1.1.0d and 1.0.2k are vulnerable.
Impact: Information Disclosure Vulnerability
Mitigation: Updates are available. Please check specific vendor advisory for more information.