CVE-2019-6111

Name	CVE-2019-6111
Description	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).
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-1728-1, DSA-4387-1, DSA-4387-2
Debian Bugs	923486

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
openssh (PTS)	bullseye, bullseye (security)	1:8.4p1-5+deb11u3	fixed
	bookworm, bookworm (security)	1:9.2p1-2+deb12u3	fixed
	sid, trixie	1:9.9p1-3	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin	Debian Bugs
openssh	source	jessie	1:6.7p1-5+deb8u8	DLA-1728-1
openssh	source	stretch	1:7.4p1-10+deb9u6	DSA-4387-2
openssh	source	(unstable)	1:7.9p1-9		923486

Notes

https://sintonen.fi/advisories/scp-client-multiple-vulnerabilities.txt
https://github.com/openssh/openssh-portable/commit/391ffc4b9d31fa1f4ad566499fef9176ff8a07dc
https://github.com/openssh/openssh-portable/commit/3d896c157c722bc47adca51a58dca859225b5874
For unstable partially fixed in 1:7.9p1-6, applied complete fix in 1:7.9p1-9.