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.

Format string vulnerability in the SSL_set_verify function in telnetd.c for SSLtelnet daemon (SSLtelnetd) 0.13 allows remote attackers to execute arbitrary code.

Race condition in the setsid function in Linux before 2.6.8.1 allows local users to cause a denial of service (crash) and possibly access portions of kernel memory, related to TTY changes, locking, and semaphores.

In NetKit through 0.17, rcp.c in the rcp client allows remote rsh servers to bypass intended access restrictions via the filename of . or an empty filename. The impact is modifying the permissions of the target directory on the client side. This is similar to CVE-2018-20685.

An issue was discovered in rcp in NetKit through 0.17. For an rcp operation, the server chooses which files/directories are sent to the client. However, the rcp client only performs cursory validation of the object name returned. A malicious rsh server (or Man-in-The-Middle attacker) can overwrite arbitrary files in a directory on the rcp client machine. This is similar to CVE-2019-6111.

netkit-rcp in rsh-client 0.17-24 allows command injection via filenames because /bin/sh is used by susystem, a related issue to CVE-2006-0225, CVE-2019-7283, and CVE-2020-15778.