In the rcp client in MIT krb5-appl through 1.0.3, malicious servers could bypass intended access restrictions via the filename of . or an empty filename, similar to CVE-2018-20685 and CVE-2019-7282. The impact is modifying the permissions of the target directory on the client side. 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.

An issue was discovered in rcp in MIT krb5-appl through 1.0.3. Due to the rcp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the rcp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious rcp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the rcp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file). This issue is similar to CVE-2019-6111 and CVE-2019-7283. 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.

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.