GNU Anubis buffer overflows and format string vulnerabilities

Ulf Härnhammar discovered several vulnerabilities in GNU Anubis.

• Unsafe uses of `sscanf'. The `%s' format specifier is used, which allows a classical buffer overflow. (auth.c)
• Format string bugs invoking `syslog'. (log.c, errs.c, ssl.c)

Ulf notes that these vulnerabilities can be exploited by a malicious IDENT server as a denial-of-service attack.