GNU inetutils before 2.5 may allow privilege escalation because of unchecked return values of set*id() family functions in ftpd, rcp, rlogin, rsh, rshd, and uucpd. This is, for example, relevant if the setuid system call fails when a process is trying to drop privileges before letting an ordinary user control the activities of the process.

telnetd in GNU Inetutils through 2.3, MIT krb5-appl through 1.0.3, and derivative works has a NULL pointer dereference via 0xff 0xf7 or 0xff 0xf8. In a typical installation, the telnetd application would crash but the telnet service would remain available through inetd. However, if the telnetd application has many crashes within a short time interval, the telnet service would become unavailable after inetd logs a "telnet/tcp server failing (looping), service terminated" error. NOTE: MIT krb5-appl is not supported upstream but is shipped by a few Linux distributions. The affected code was removed from the supported MIT Kerberos 5 (aka krb5) product many years ago, at version 1.8.

The ftp client in GNU Inetutils before 2.2 does not validate addresses returned by PASV/LSPV responses to make sure they match the server address. This is similar to CVE-2020-8284 for curl.

Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT Kerberos Version 5 Applications (aka krb5-appl) 1.0.2 and earlier, Heimdal 1.5.1 and earlier, GNU inetutils, and possibly other products allows remote attackers to execute arbitrary code via a long encryption key, as exploited in the wild in December 2011.