CVE-2016-7055 Information
Share on: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.
CVSS Vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Reference
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html http://www.securityfocus.com/bid/94242 http://www.securitytracker.com/id/1037261 https://access.redhat.com/errata/RHSA-2018:2185 https://access.redhat.com/errata/RHSA-2018:2186 https://access.redhat.com/errata/RHSA-2018:2187 https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbgn03752en_us https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03744en_us https://security.FreeBSD.org/advisories/FreeBSD-SA-17:02.openssl.asc https://security.gentoo.org/glsa/201702-07 https://www.openssl.org/news/secadv/20161110.txt https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html https://www.tenable.com/security/tns-2017-04
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction Required
NONE
Scope
NONE
Confidentiality Impact
UNCHANGED
Integrity Impact
NONE
Availability Impact
NONE
Base Score
HIGH
Base Severity
5.9