GCVE-110-MAGEIA-2021-196

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 (CVE-2019-25017). 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 (CVE-2019-25018).