Advisories ยป MGASA-2021-0196

Updated krb5-appl packages fix security vulnerabilities

Publication date: 23 Apr 2021
Type: security
Affected Mageia releases : 7 , 8
CVE: CVE-2019-25017 , CVE-2019-25018


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).