Detections
Analytics
CVE-2016-7055
medium
Description
There is a carry propagating bug in the Broadwell-specific Montgomery multiplication procedure in OpenSSL 1.0.2 and 1.1.0 before 1.1.0c that handles input lengths divisible by, but longer than 256 bits. Analysis suggests that attacks against RSA, DSA and DH private keys are impossible. This is because the subroutine in question is not used in operations with the private key itself and an input of the attacker's direct choice. Otherwise the bug can manifest itself as transient authentication and key negotiation failures or reproducible erroneous outcome of public-key operations with specially crafted input. Among EC algorithms only Brainpool P-512 curves are affected and one presumably can attack ECDH key negotiation. Impact was not analyzed in detail, because pre-requisites for attack are considered unlikely. Namely multiple clients have to choose the curve in question and the server has to share the private key among them, neither of which is default behaviour. Even then only clients that chose the curve will be affected.
References
https://www.tenable.com/security/tns-2017-04
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
https://www.openssl.org/news/secadv/20161110.txt
https://security.gentoo.org/glsa/201702-07
https://security.FreeBSD.org/advisories/FreeBSD-SA-17:02.openssl.asc
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03744en_us
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbgn03752en_us
https://access.redhat.com/errata/RHSA-2018:2187
https://access.redhat.com/errata/RHSA-2018:2186
https://access.redhat.com/errata/RHSA-2018:2185
http://www.securitytracker.com/id/1037261
http://www.securityfocus.com/bid/94242
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html