pidgin is vulnerable to arbitrary code execution attacks. The vulnerability exists through a buffer overflow issue in http.c in the MXit protocol plugin in libpurple in Pidgin before 2.10.7 allows remote servers to execute arbitrary code via a long HTTP header.
hg.pidgin.im/pidgin/main/rev/879db2a9a59c
lists.opensuse.org/opensuse-security-announce/2013-03/msg00003.html
lists.opensuse.org/opensuse-security-announce/2013-03/msg00006.html
lists.opensuse.org/opensuse-security-announce/2013-03/msg00007.html
www.pidgin.im/news/security/?id=66
www.securityfocus.com/bid/57951
www.ubuntu.com/usn/USN-1746-1
access.redhat.com/security/updates/classification/#moderate
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17474
rhn.redhat.com/errata/RHSA-2013-0646.html