Bug was found in OpenSSH 6.8 and 6.9. Incorrectly set TTYs to be world-writable allow local attackers to be able to write arbitrary messages to logged-in users, including terminal escape sequences. Upstream patch: https://anongit.mindrot.org/openssh.git/commit/?id=6f941396b6835ad18018845f515b0c4fe20be21a http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshpty.c.diff?r1=1.29&r2=1.30&f=h CVE request: http://seclists.org/oss-sec/2015/q3/327 External References: http://www.openssh.com/txt/release-7.0
Created openssh tracking bugs for this issue: Affects: fedora-all [bug 1252862]
openssh-7.0p1-1.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
openssh-6.9p1-5.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
CVE assignment: http://seclists.org/oss-sec/2015/q3/419
Interesting observation of how to exploit this vulnerability for code execution as the targeted user: http://seclists.org/oss-sec/2015/q3/482
This issue was introduced in the following upstream commit: https://anongit.mindrot.org/openssh.git/commit/sshpty.c?id=a5883d4eccb94b16c355987f58f86a7dee17a0c2 http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/sshpty.c.diff?r1=1.28&r2=1.29&f=h That commit intentionally changed TTY permissions for systems without the tty group from S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH (622) to 600, but also unintentionally changed permissions for systems with the tty group from S_IRUSR | S_IWUSR | S_IWGRP (620) to 622. The openssh versions as shipped Red Hat Enterprise Linux 7 and earlier did not include the above incorrect change and hence were not affected by this issue. Statement: This issue did not affect the versions of openssh as shipped with Red Hat Enterprise Linux 5, 6, and 7.