View at Official ubuntu advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2012-4561 low priority: Ubuntu including 1 source packages (libssh), 6 status rows across 6 suites (hardy, lucid, oneiric, precise, quantal, upstream): released 5, ignored 1.
The (1) publickey_make_dss, (2) publickey_make_rsa, (3) signature_from_string, (4) ssh_do_sign, and (5) ssh_sign_session_id functions in keys.c in libssh before 0.5.3 free "an invalid pointer on an error path," which might allow remote attackers to cause a denial of service (crash) via unspecified vectors.