CVE-2016-0702 – OpenSSL: Side channel attack on modular exponentiation

https://notcve.org/view.php?id=CVE-2016-0702

The MOD_EXP_CTIME_COPY_FROM_PREBUF function in crypto/bn/bn_exp.c in OpenSSL 1.0.1 before 1.0.1s and 1.0.2 before 1.0.2g does not properly consider cache-bank access times during modular exponentiation, which makes it easier for local users to discover RSA keys by running a crafted application on the same Intel Sandy Bridge CPU core as a victim and leveraging cache-bank conflicts, aka a "CacheBleed" attack. La función MOD_EXP_CTIME_COPY_FROM_PREBUF en crypto/bn/bn_exp.c en OpenSSL 1.0.1 en versiones anteriores a 1.0.1s y 1.0.2 en versiones anteriores a 1.0.2g no considera correctamente las veces que se accede al cache-bank durante la exponenciación modular, lo que facilita a usuarios locales descubrir las claves RSA ejecutando una aplicación manipulada en el mismo núcleo de la CPU Intel Sandy Bridge como víctima y aprovechándose de los conflictos del cache-bank, también conocida como un ataque "CacheBleed". A side-channel attack was found that makes use of cache-bank conflicts on the Intel Sandy-Bridge microarchitecture. An attacker who has the ability to control code in a thread running on the same hyper-threaded core as the victim's thread that is performing decryption, could use this flaw to recover RSA private keys. • http://cachebleed.info http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10759 http://lists.fedoraproject.org/pipermail/package-announce/2016-March/178358.html http://lists.fedoraproject.org/pipermail/package-announce/2016-March/178817.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00001.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00002.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00003.html http://lists.opensuse.org/opensuse- • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor •