CVE-2015-0837

La función mpi_powm en Libgcrypt versiones anteriores a 1.6.3 y GnuPG versiones anteriores a 1.4.19, permite a atacantes obtener información confidencial mediante el aprovechamiento de las diferencias de tiempo al acceder a una tabla precalculada durante una exponenciación modular, relacionada con un "Last-Level Cache Side-Channel Attack".

Updated gnupg, gnupg2 and libgcrypt packages fix security GnuPG versions before 1.4.17 and 2.0.24 are vulnerable to a denial of service which can be caused by garbled compressed data packets which may put gpg into an infinite loop. The libgcrypt library before version 1.5.4 is vulnerable to an ELGAMAL side-channel attack. GnuPG before 1.4.19 is vulnerable to a side-channel attack which can potentially lead to an information leak. GnuPG before 1.4.19 is vulnerable to a side-channel attack on data-dependent timing variations in modular exponentiation, which can potentially lead to an information leak. The gnupg and gnupg2 package has been patched to correct these issues. GnuPG2 is vulnerable to these issues through the libgcrypt library. The issues were fixed in libgcrypt 1.6.3. The libgcrypt package in Mandriva, at version 1.5.4, was only vulnerable to the CVE-2014-3591 issue. It has also been patched to correct this issue.