[3.8] openssh: Multiple vulnerabilities (CVE-2018-20685, CVE-2019-6109, CVE-2019-6111)
CVE-2018-20685: In OpenSSH 7.9, scp.c in the scp client allows
remote SSH 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.
CVE-2019-6109: An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affects refresh_progress_meter() in progressmeter.c.
possibly additionally needed: https://github.com/openssh/openssh-portable/commit/bdc6c63c80b55bcbaa66b5fde31c1cb1d09a41eb
CVE-2019-6111: An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp 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).
(from redmine: issue id 9998, created on 2019-02-20, closed on 2019-03-05)
main/openssh: security fixes CVE-2018-20685, CVE-2019-6109, CVE-2019-6111 Rebase HPN patch fixes #9998