CVE-2016-1908: Debian Linux

Critical severity, CVSS 9.8. EPSS: 13.7% chance of exploitation in the next 30 days.

The client in OpenSSH before 7.2 mishandles failed cookie generation for untrusted X11 forwarding and relies on the local X11 server for access-control decisions, which allows remote X11 clients to trigger a fallback and obtain trusted X11 forwarding privileges by leveraging configuration issues on this X11 server, as demonstrated by lack of the SECURITY extension on this X11 server.

Affected products

• Debian Debian Linux: version 8.0 only
• OpenBSD OpenSSH: before 7.2 (fixed in 7.2)
• Oracle Linux: version 6 only; version 7 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Eus: version 7.2 only; version 7.3 only; version 7.4 only; version 7.5 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.2 only; version 7.3 only; version 7.4 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Server Tus: version 7.2 only; version 7.3 only; version 7.6 only; version 7.7 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2017-04-11. Last modified 2026-06-17.