Multiple double free vulnerabilities in the (1) agent_sign_data function in agent.c, (2) channel_request function in channels.c, (3) ssh_userauth_pubkey function in auth.c, (4) sftp_parse_attr_3 function in sftp.c, and (5) try_publickey_from_file function in keyfiles.c in libssh before 0.5.3 allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors.
http://lists.fedoraproject.org/pipermail/package-announce/2012-November/093313.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-November/093474.html
http://lists.opensuse.org/opensuse-security-announce/2012-12/msg00002.html
http://lists.opensuse.org/opensuse-updates/2012-12/msg00016.html
http://lists.opensuse.org/opensuse-updates/2013-01/msg00021.html
https://bugzilla.redhat.com/show_bug.cgi?id=871612
https://exchange.xforce.ibmcloud.com/vulnerabilities/80218
http://www.debian.org/security/2012/dsa-2577
http://www.mandriva.com/security/advisories?name=MDVSA-2012:175