KTH Kerberos IV and Kerberos V (Heimdal) for Telnet clients do not encrypt connections if the server does not support the requested encryption, which allows remote attackers to read communications via a man-in-the-middle attack.

The Kerberos Telnet protocol, as implemented by KTH Kerberos IV and Kerberos V (Heimdal), does not encrypt authentication and encryption options sent from the server, which allows remote attackers to downgrade authentication and encryption mechanisms via a man-in-the-middle attack.

Buffer overflow in BSD-based telnetd telnet daemon on various operating systems allows remote attackers to execute arbitrary commands via a set of options including AYT (Are You There), which is not properly handled by the telrcv function.

Kerberos 4 (aka krb4) allows local users to overwrite arbitrary files via a symlink attack on new ticket files.

Buffer overflows in BSD-based FTP servers allows remote attackers to execute arbitrary commands via a long pattern string containing a {} sequence, as seen in (1) g_opendir, (2) g_lstat, (3) g_stat, and (4) the glob0 buffer as used in the glob functions glob2 and glob3.

KTH Kerberos IV allows local users to change the configuration of a Kerberos server running at an elevated privilege by specifying an alternate directory using with the KRBCONFDIR environmental variable, which allows the user to gain additional privileges.

Buffer overflow in the kdc_reply_cipher function in KTH Kerberos IV allows remote attackers to cause a denial of service and possibly execute arbitrary commands via a long authentication request.

KTH Kerberos IV allows local users to overwrite arbitrary files via a symlink attack on a ticket file.

Buffer overflow in Kerberos 4 KDC program allows remote attackers to cause a denial of service via the lastrealm variable in the set_tgtkey function.

Buffer overflow in Kerberos 4 KDC program allows remote attackers to cause a denial of service via the e_msg variable in the kerb_err_reply function.