Auth bypass in OpenBSD OpenSSH
CVE-2016-1908
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.137 (96.4th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 96.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.137 · newest: 0.137 · change: 0.000
Affected products
- OpenBSD OpenSSH
- Oracle Linux — versions 6, 7
- Debian Linux — versions 8.0
- Red Hat Enterprise Linux Desktop — versions 6.0, 7.0
- Red Hat Enterprise Linux Eus — versions 7.2, 7.3, 7.4
- Red Hat Enterprise Linux Server — versions 6.0, 7.0
- Red Hat Enterprise Linux Server Aus — versions 7.2, 7.3, 7.4
- Red Hat Enterprise Linux Server Tus — versions 7.2, 7.3, 7.6
- Red Hat Enterprise Linux Workstation — versions 6.0, 7.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.openssh.com/txt/release-7.2 (Release Notes, Vendor Advisory)
- www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html (Third Party Advisory)
- anongit.mindrot.org/openssh.git/commit/ (Patch, Third Party Advisory)
- openwall.com/lists/oss-security/2016/01/15/13 (mailing-list, Mailing List, Third Party Advisory)
- www.securitytracker.com/id/1034705 (VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
- rhn.redhat.com/errata/RHSA-2016-0741.html (vendor-advisory, Third Party Advisory)
- security.gentoo.org/glsa/201612-18 (vendor-advisory, Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- lists.debian.org/debian-lts-announce/2018/09/msg00010.html (mailing-list, Mailing List, Third Party Advisory)
- www.securityfocus.com/bid/84427 (VDB Entry, Third Party Advisory, vdb-entry)
Frequently asked questions
- What is CVE-2016-1908?
- CVE-2016-1908 is a critical-severity vulnerability in OpenBSD OpenSSH, classified under Improper Authentication. CVSS score: 9.8/10. Published 2017-04-11.
- How severe is CVE-2016-1908?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2016-1908 known to be exploited?
- 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.