Double free vulnerability in the sftp_mkdir function in sftp.c in libssh before 0.5.3 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors, a different vector than CVE-2012-4559.
https://bugzilla.redhat.com/show_bug.cgi?id=871612
http://www.libssh.org/2012/11/20/libssh-0-5-3-security-release/
http://www.debian.org/security/2012/dsa-2577
http://git.libssh.org/projects/libssh.git/commit/?h=v0-5&id=4d8420f3282ed07fc99fc5e930c17df27ef1e9b2