// For flags

CVE-2016-1908

openssh: possible fallback from untrusted to trusted X11 forwarding

Severity Score

9.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

El cliente en OpenSSH en versiones anteriores a 7.2 no maneja correctamente falló en la generación de cookies para el reenvío X11 no confiable y confía en el servidor X11 local para las decisiones de control de acceso, lo que permite a los clientes remotos X11 activar un fallback y obtener privilegios de reenvío X11 confiables aprovechando los problemas de configuración de este servidor X11, como lo demuestra la falta de la extensión SECURITY en este servidor X11.

An access flaw was discovered in OpenSSH; the OpenSSH client did not correctly handle failures to generate authentication cookies for untrusted X11 forwarding. A malicious or compromised remote X application could possibly use this flaw to establish a trusted connection to the local X server, even if only untrusted X11 forwarding was requested.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
Attack Vector
Network
Attack Complexity
Medium
Authentication
Single
Confidentiality
Partial
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2016-01-15 CVE Reserved
  • 2016-03-22 CVE Published
  • 2023-07-16 EPSS Updated
  • 2024-08-05 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-284: Improper Access Control
  • CWE-287: Improper Authentication
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Openbsd
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Openssh
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< 7.2
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-
Affected
Debian
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Debian Linux
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8.0
Search vendor "Debian" for product "Debian Linux" and version "8.0"
-
Affected
Oracle
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Linux
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6
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-
Affected
Oracle
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Linux
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7
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-
Affected
Redhat
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Enterprise Linux Desktop
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6.0
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-
Affected
Redhat
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Enterprise Linux Desktop
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7.0
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-
Affected
Redhat
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Enterprise Linux Eus
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7.2
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-
Affected
Redhat
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Enterprise Linux Eus
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7.3
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-
Affected
Redhat
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Enterprise Linux Eus
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7.4
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-
Affected
Redhat
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Enterprise Linux Eus
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7.5
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-
Affected
Redhat
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Enterprise Linux Eus
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7.6
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-
Affected
Redhat
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Enterprise Linux Eus
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7.7
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-
Affected
Redhat
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Enterprise Linux Server
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6.0
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-
Affected
Redhat
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Enterprise Linux Server
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7.0
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.2
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-
Affected
Redhat
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Enterprise Linux Server Aus
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7.3
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Affected
Redhat
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Enterprise Linux Server Aus
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7.4
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Affected
Redhat
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Enterprise Linux Server Aus
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7.6
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Affected
Redhat
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Enterprise Linux Server Aus
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7.7
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.2
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-
Affected
Redhat
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Enterprise Linux Server Tus
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7.3
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Affected
Redhat
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Enterprise Linux Server Tus
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7.6
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Affected
Redhat
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Enterprise Linux Server Tus
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7.7
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-
Affected
Redhat
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Enterprise Linux Workstation
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6.0
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-
Affected
Redhat
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Enterprise Linux Workstation
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7.0
Search vendor "Redhat" for product "Enterprise Linux Workstation" and version "7.0"
-
Affected