CRITICAL
openssh: possible fallback from untrusted to trusted X11 forwarding
Published Apr 11, 2017
9.8
CRITICALCVSS 3.1
EPSS 13.74%
Description
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
No data.
Configuration 2
- 8.0
Configuration 4
OR
- 6.0
- 7.0
- 7.2
- 7.3
- 7.4
- 7.5
- 7.6
- 7.7
- 6.0
- 7.0
- 7.2
- 7.3
- 7.4
- 7.6
- 7.7
- 7.2
- 7.3
- 7.6
- 7.7
- 6.0
- 7.0
No data.
Red Hat Enterprise Linux 6
openssh-0:5.3p1-117.el6
Fixed · RHSA-2016:0741
Red Hat Enterprise Linux 7
openssh-0:6.6.1p1-25.el7_2
Fixed · RHSA-2016:0465
Red Hat Enterprise Linux 5
openssh
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | openssh-0:5.3p1-117.el6 | Fixed | RHSA-2016:0741 |
| Red Hat Enterprise Linux 7 | openssh-0:6.6.1p1-25.el7_2 | Fixed | RHSA-2016:0465 |
| Red Hat Enterprise Linux 5 | openssh | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
9.8 CRITICAL NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact High
No CVSS v3.0 score for this CVE.
7.5 HIGH NVD
AV:N/AC:L/Au:N/C:P/I:P/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact Partial
Integrity Impact Partial
Availability Impact Partial
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
TotalDecision
n/aAssessed May 29, 2026 · SSVC 2.0.3
13.74% 0.13736
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
EPSS probability 0.13736
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (51 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 13.74% (0.13736) | 96.40th | v5 (v2026.06.15) |
| Jun 15, 2026 | 13.74% (0.13736) | 96.01th | v5 (v2026.06.15) |
| Mar 4, 2026 | 2.54% (0.02538) | 85.19th | v4 (v2025.03.14) |
| Mar 1, 2026 | 0.93% (0.00926) | 75.84th | v4 (v2025.03.14) |
| Feb 4, 2026 | 2.43% (0.02433) | 84.79th | v4 (v2025.03.14) |
| Feb 1, 2026 | 0.90% (0.00902) | 75.36th | v4 (v2025.03.14) |
| Jan 4, 2026 | 2.37% (0.02368) | 84.51th | v4 (v2025.03.14) |
| Jan 1, 2026 | 0.88% (0.00877) | 74.91th | v4 (v2025.03.14) |
| Dec 28, 2025 | 2.37% (0.02368) | 84.51th | v4 (v2025.03.14) |
| Dec 27, 2025 | 4.36% (0.04362) | 88.63th | v4 (v2025.03.14) |
| Dec 4, 2025 | 2.40% (0.02402) | 84.56th | v4 (v2025.03.14) |
| Dec 1, 2025 | 0.83% (0.00835) | 73.98th | v4 (v2025.03.14) |
| Nov 4, 2025 | 2.54% (0.02538) | 84.91th | v4 (v2025.03.14) |
| Nov 1, 2025 | 0.93% (0.00926) | 75.44th | v4 (v2025.03.14) |
| Oct 28, 2025 | 2.54% (0.02538) | 84.89th | v4 (v2025.03.14) |
| Oct 27, 2025 | 4.67% (0.04666) | 88.85th | v4 (v2025.03.14) |
| Oct 4, 2025 | 2.54% (0.02538) | 84.89th | v4 (v2025.03.14) |
| Oct 1, 2025 | 0.93% (0.00926) | 75.35th | v4 (v2025.03.14) |
| Sep 4, 2025 | 4.67% (0.04666) | 88.91th | v4 (v2025.03.14) |
| Sep 1, 2025 | 1.55% (0.01546) | 80.77th | v4 (v2025.03.14) |
| Aug 4, 2025 | 4.42% (0.04423) | 88.60th | v4 (v2025.03.14) |
| Aug 1, 2025 | 1.40% (0.01395) | 79.68th | v4 (v2025.03.14) |
| Jul 30, 2025 | 4.42% (0.04423) | 88.59th | v4 (v2025.03.14) |
| Jul 4, 2025 | 2.40% (0.02402) | 84.39th | v4 (v2025.03.14) |
| Jul 1, 2025 | 0.83% (0.00835) | 73.71th | v4 (v2025.03.14) |
| Jun 4, 2025 | 2.18% (0.02179) | 83.52th | v4 (v2025.03.14) |
| Jun 1, 2025 | 0.94% (0.00940) | 75.22th | v4 (v2025.03.14) |
| May 5, 2025 | 2.18% (0.02179) | 83.41th | v4 (v2025.03.14) |
| May 1, 2025 | 0.94% (0.00940) | 75.10th | v4 (v2025.03.14) |
| Apr 18, 2025 | 2.24% (0.02238) | 83.61th | v4 (v2025.03.14) |
| Apr 17, 2025 | 0.97% (0.00966) | 75.33th | v4 (v2025.03.14) |
| Apr 11, 2025 | 2.18% (0.02179) | 82.96th | v4 (v2025.03.14) |
| Apr 10, 2025 | 0.94% (0.00940) | 74.29th | v4 (v2025.03.14) |
| Apr 8, 2025 | 2.18% (0.02179) | 82.93th | v4 (v2025.03.14) |
| Apr 7, 2025 | 0.94% (0.00940) | 74.26th | v4 (v2025.03.14) |
| Apr 4, 2025 | 2.18% (0.02179) | 82.92th | v4 (v2025.03.14) |
| Apr 2, 2025 | 0.94% (0.00940) | 74.25th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.18% (0.02179) | 82.84th | v4 (v2025.03.14) |
| Mar 29, 2025 | 6.85% (0.06848) | 85.23th | v4 (v2025.03.14) |
| Mar 28, 2025 | 0.94% (0.00940) | 74.17th | v4 (v2025.03.14) |
| Mar 23, 2025 | 2.18% (0.02179) | 81.18th | v4 (v2025.03.14) |
| Mar 22, 2025 | 0.94% (0.00940) | 74.25th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.18% (0.02179) | 83.19th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.50% (0.00503) | 77.20th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.36% (0.00365) | 71.65th | v3 (v2023.03.01) |
| Jul 16, 2023 | 0.36% (0.00365) | 68.70th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.52% (0.00516) | 73.10th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.54% (0.01537) | 74.48th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.54% (0.01537) | 72.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.54% (0.01537) | 51.33th | v2 (v2022.01.01) |
Weaknesses (2)
References (15)
- http://openwall.com/lists/oss-security/2016/01/15/13 mailing-listMailing ListThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-0465.html vendor-advisoryThird Party Advisory
- http://rhn.redhat.com/errata/RHSA-2016-0741.html vendor-advisoryThird Party Advisory
- http://www.openssh.com/txt/release-7.2 Release NotesVendor Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html Third Party Advisory
- http://www.securityfocus.com/bid/84427 vdb-entryThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1034705 vdb-entryBroken LinkThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2016-1908 Vendor Advisory
- https://anongit.mindrot.org/openssh.git/commit/?id=ed4ce82dbfa8a3a3c8ea6fa0db113c71e234416c PatchThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1298741 Issue TrackingPatchThird Party Advisory
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html mailing-listMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2016-1908
- https://security.gentoo.org/glsa/201612-18 vendor-advisoryThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2016-1908
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner redhat
Published Apr 11, 2017
Updated May 29, 2026
Reserved Jan 15, 2016
Link CVE-2016-1908
CISA Vulnrichment
Updated May 29, 2026