DSA-2526 libotr - heap-based buffer overflows

Just Ferguson discovered that libotr, an off-the-record (OTR) messaging
library, can be forced to perform zero-length allocations for heap buffers
that are used in base64 decoding routines. An attacker can exploit this
flaw by sending crafted messages to an application that is using libotr to
perform denial of service attacks or potentially execute arbitrary code.