The Montgomery squaring implementation in crypto/bn/asm/x86_64-mont5.pl in OpenSSL 1.0.2 before 1.0.2e on the x86_64 platform, as used by the BN_mod_exp function, mishandles carry propagation and produces incorrect output, which makes it easier for remote attackers to obtain sensitive private-key information via an attack against use of a (1) Diffie-Hellman (DH) or (2) Diffie-Hellman Ephemeral (DHE) ciphersuite.
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA40100
https://kb.isc.org/article/AA-01438
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05398322
https://git.openssl.org/?p=openssl.git%3Ba=commit%3Bh=d73cc256c8e256c32ed959456101b73ba9842f72
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
https://bugzilla.redhat.com/show_bug.cgi?id=1288317
http://www.ubuntu.com/usn/USN-2830-1
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2015&m=slackware-security.754583
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2015&m=slackware-security.539966
http://www.securitytracker.com/id/1034294
http://www.securityfocus.com/bid/91787
http://www.securityfocus.com/bid/78705
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
http://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html
http://www.fortiguard.com/advisory/openssl-advisory-december-2015
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151204-openssl
http://openssl.org/news/secadv/20151203.txt
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10761
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10759
http://fortiguard.com/advisory/openssl-advisory-december-2015