Multiple scp client vulnerabilities have been discovered in OpenSSH, the premier connectivity tool for secure remote shell login and secure file transfer.

CVE-2018-20685

In scp.c, the scp client allowed remote SSH servers to bypass intended access restrictions via the filename of . or an empty filename. The impact was modifying the permissions of the target directory on the client side.

CVE-2019-6109

Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) was able to employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affected refresh_progress_meter() in progressmeter.c.

CVE-2019-6111

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 performed cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) was able to overwrite arbitrary files in the scp client target directory. If recursive operation (-r) was performed, the server was able to manipulate subdirectories, as well (for example, to overwrite the .ssh/authorized_keys file).

For Debian 8 'Jessie', these problems have been fixed in version 1:6.7p1-5+deb8u8.

We recommend that you upgrade your openssh packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Detections

Analytics

Debian DLA-1728-1 : openssh security update

medium Nessus Plugin ID 123095

Version 1.6