Buffer overflow in the RPC library used by libgssrpc and kadmind in MIT Kerberos 5 (krb5) 1.4 through 1.6.3 allows remote attackers to execute arbitrary code by triggering a large number of open file descriptors.

The original patch for CVE-2007-3999 in svc_auth_gss.c in the RPCSEC_GSS RPC library in MIT Kerberos 5 (krb5) 1.4 through 1.6.2, as used by the Kerberos administration daemon (kadmind) and other applications that use krb5, does not correctly check the buffer length in some environments and architectures, which might allow remote attackers to conduct a buffer overflow attack.

Stack-based buffer overflow in the svcauth_gss_validate function in lib/rpc/svc_auth_gss.c in the RPCSEC_GSS RPC library (librpcsecgss) in MIT Kerberos 5 (krb5) 1.4 through 1.6.2, as used by the Kerberos administration daemon (kadmind) and some third-party applications that use krb5, allows remote attackers to cause a denial of service (daemon crash) and probably execute arbitrary code via a long string in an RPC message.

sudo, when linked with MIT Kerberos 5 (krb5), does not properly check whether a user can currently authenticate to Kerberos, which allows local users to gain privileges, in a manner unintended by the sudo security model, via certain KRB5_ environment variable settings. NOTE: another researcher disputes this vulnerability, stating that the attacker must be "a user, who can already log into your system, and can already use sudo."