CVE-2017-3736 Information disclosure in OpenSSL
A carry propagation bug in OpenSSL's Montgomery squaring may allow attackers to deduce private key information from Diffie-Hellman operations under specific conditions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-3736?
CVE-2017-3736 is a medium-severity vulnerability in Openssl Openssl, published on 2 Nov 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-200
Which versions are affected by CVE-2017-3736?
It affects 1 product.
Products include Openssl Openssl.
How do I fix CVE-2017-3736?
Upgrade to a fixed version.
Is CVE-2017-3736 being exploited?
There is no known exploitation of CVE-2017-3736 in the wild and no public exploit code.
Other vulnerabilities in Openssl Openssl
Sources
Also known as ALPINE-CVE-2017-3736, AZL-84296, DEBIAN-CVE-2017-3736, GHSA-72w7-9ghx-p5pg, UBUNTU-CVE-2017-3736.