The (1) roaming_read and (2) roaming_write functions in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2, when certain proxy and forward options are enabled, do not properly maintain connection file descriptors, which allows remote servers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact by requesting many forwardings.

According to its banner, the version of OpenSSH running on the remote host is 5.x prior to 5.4, 6.x or 7.x prior to 7.1p2. It is, therefore, affected by multiple vulnerabilities. 

  - A potential information disclosure vulnerability which     may allow remote servers to obtain sensitive information     from process memory by requesting transmission of an     entire buffer (CVE-2016-0777)

  - A denial of service vulnerability due to a heap-base     overflow in roaming_common.c (CVE-2016-0778)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to its self-reported version number, the remote pfSense install is prior to 2.3. It is, therefore, affected by multiple vulnerabilities.

The remote host is running a version of Mac OS X version 10.11.x prior to 10.11.4 and is affected by multiple vulnerabilities in the following components :

 - apache_mod_php
 - AppleRAID
 - AppleUSBNetworking
 - Bluetooth
 - Carbon
 - dyld
 - FontParser
 - HTTPProtocol
 - Intel Graphics Driver
 - IOFireWireFamily
 - IOGraphics
 - IOHIDFamily
 - IOUSBFamily
 - Kernel
 - libxml2
 - Messages
 - NVIDIA Graphics Drivers
 - OpenSSH
 - OpenSSL
 - Python
 - QuickTime
 - Reminders
 - Ruby
 - Security
 - Tcl
 - TrueTypeScaler
 - Wi-Fi

Note that successful exploitation of the most serious issues can result in arbitrary code execution.

The remote host is running a version of Mac OS X that is 10.9.5 or 10.10.5 and is missing Security Update 2016-002. It is, therefore, affected by multiple vulnerabilities in the following components :

  - apache_mod_php
  - Kernel
  - libxml2
  - OpenSSH
  - Python
  - Tcl

Note that successful exploitation of the most serious issues can result in arbitrary code execution.

The remote host is running a version of Mac OS X that is 10.11.x prior to 10.11.4. It is, therefore, affected by multiple vulnerabilities in the following components :

  - apache_mod_php
  - AppleRAID
  - AppleUSBNetworking
  - Bluetooth
  - Carbon
  - dyld
  - FontParser
  - HTTPProtocol
  - Intel Graphics Driver
  - IOFireWireFamily
  - IOGraphics
  - IOHIDFamily
  - IOUSBFamily
  - Kernel
  - libxml2
  - Messages
  - NVIDIA Graphics Drivers
  - OpenSSH
  - OpenSSL
  - Python
  - QuickTime
  - Reminders
  - Ruby
  - Security
  - Tcl
  - TrueTypeScaler
  - Wi-Fi

Note that successful exploitation of the most serious issues can result in arbitrary code execution.

Sync with latest openssh package.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote AIX host has a version of OpenSSH installed that is affected by the following vulnerabilities :

  - An information disclosure vulnerability exists in the     resend_bytes() function in the undocumented roaming     connection feature. An authenticated, remote attacker     can exploit this vulnerability, by persuading a victim     to connect to a malicious server, to retrieve private     cryptographic keys or other sensitive information.
    (CVE-2016-0777)

  - A heap-based buffer overflow condition exists in the     undocumented roaming connection feature due to improper     bounds checking of user-supplied input to the     packet_write_wait() and ssh_packet_write_wait()     functions whenever the non-default option ProxyCommand     is used with either ForwardAgent or ForwardX11. An     authenticated, remote attacker can exploit this     vulnerability, by persuading a victim to connect to a     malicious server, to execute arbitrary code or cause     a denial of service. (CVE-2016-0778)

- CVE-2016-0777: A malicious or compromised server could     cause the OpenSSH client to expose part or all of the     client's private key through the roaming feature     (bsc#961642)

  - CVE-2016-0778: A malicious or compromised server could     could trigger a buffer overflow in the OpenSSH client     through the roaming feature (bsc#961645)

This update disables the undocumented feature supported by the OpenSSH client and a commercial SSH server.

This update for openssh fixes the following issues :

  - CVE-2016-0777: A malicious or compromised server could     cause the OpenSSH client to expose part or all of the     client's private key through the roaming feature     (bsc#961642)

  - CVE-2016-0778: A malicious or compromised server could     could trigger a buffer overflow in the OpenSSH client     through the roaming feature (bsc#961645)

This update disables the undocumented feature supported by the OpenSSH client and a commercial SSH server.

This update for openssh fixes the following issues :

  - CVE-2016-0777: A malicious or compromised server could     cause the OpenSSH client to expose part or all of the     client's private key through the roaming feature     (bsc#961642)

  - CVE-2016-0778: A malicious or compromised server could     could trigger a buffer overflow in the OpenSSH client     through the roaming feature (bsc#961645)

This update disables the undocumented feature supported by the OpenSSH client and a commercial SSH server.

This update was imported from the SUSE:SLE-12:Update update project.

The remote host is affected by the vulnerability described in GLSA-201601-01 (OpenSSH: Multiple vulnerabilities)

    Qualys have reported two issues in the &ldquo;roaming&rdquo; code included in       the OpenSSH client, which provides undocumented, experimental support for       resuming SSH connections. An OpenSSH client could be tricked into leaking       parts of its memory to a malicious server. Furthermore, a buffer overflow       can be exploited by a malicious server, but its exploitation requires       non-default options and is mitigated due to another bug.
  Impact :

    A remote attacker could entice a user to connect to a specially crafted       OpenSSH server, possibly resulting in the disclosure of the user&rsquo;s       private keys. Users with private keys that are not protected by a       passphrase are advised to generate new keys if they have connected to an       SSH server they don&rsquo;t fully trust.
    Note that no special configuration is required to be vulnerable as the       roaming feature is enabled by default on the client.
  Workaround :

    The issues can be worked around by disabling the roaming code. To do so,       add &ldquo;UseRoaming no&rdquo; to the SSH client configuration, or specify &ldquo;-o       &lsquo;UseRoaming no&rsquo;&rdquo; on the command line.

An information leak flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to leak portions of memory (possibly including private SSH keys) of a successfully authenticated OpenSSH client.

A buffer overflow flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to execute arbitrary code on a successfully authenticated OpenSSH client if that client used certain non-default configuration options.

This update for openssh fixes the following issues :

  - CVE-2016-0777: A malicious or compromised server could     cause the OpenSSH client to expose part or all of the     client's private key through the roaming feature     (bsc#961642)

  - CVE-2016-0778: A malicious or compromised server could     could trigger a buffer overflow in the OpenSSH client     through the roaming feature (bsc#961645)

This update disables the undocumented feature supported by the OpenSSH client and a commercial SSH server.

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Versions of OpenSSH prior to 7.1p2 are affected by multiple vulnerabilities:

 - Using a specially crafted SSH server, a context-dependent attacker can disclose sensitive memory contents when the client authenticates to the server, such as the client's private SSH keys. (CVE-2016-0777)
 - An unspecified overflow condition exists that is triggered as user-supplied input is not properly validated. With a specially crafted SSH server, a context-dependent attacker can cause a buffer overflow, potentially allowing the execution of arbitrary code. (CVE-2016-0778)

Note: NNM has solely relied on the banner of the SSH client to perform this check. Any backported patches or workarounds such as recompiling or edited configurations are not observable through the banner.
 - A vulnerability exists that allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via crafted network traffic. (CVE-2016-1907)

The remote Ubuntu 14.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-2869-1 advisory.

    It was discovered that the OpenSSH client experimental support for resuming connections contained multiple     security issues. A malicious server could use this issue to leak client memory to the server, including     private client user keys.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An information leak flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to leak portions of memory (possibly including private SSH keys) of a successfully authenticated OpenSSH client.
(CVE-2016-0777)

A buffer overflow flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to execute arbitrary code on a successfully authenticated OpenSSH client if that client used certain non-default configuration options.
(CVE-2016-0778)

After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

Updated openssh packages that fix two security issues are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages include the core files necessary for both the OpenSSH client and server.

An information leak flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to leak portions of memory (possibly including private SSH keys) of a successfully authenticated OpenSSH client.
(CVE-2016-0777)

A buffer overflow flaw was found in the way the OpenSSH client roaming feature was implemented. A malicious server could potentially use this flaw to execute arbitrary code on a successfully authenticated OpenSSH client if that client used certain non-default configuration options.
(CVE-2016-0778)

Red Hat would like to thank Qualys for reporting these issues.

All openssh users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.

The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2016-0043 advisory.

    [6.6.1p1-23 + 0.9.3-9]
    - Disable undocumented feauture Roaming for good (#1298218)
    - prevents CVE-2016-0777 and CVE-2016-0778

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

OpenSSH reports :

OpenSSH clients between versions 5.4 and 7.1 are vulnerable to information disclosure that may allow a malicious server to retrieve information including under some circumstances, user's private keys.

The Qualys Security team discovered two vulnerabilities in the roaming code of the OpenSSH client (an implementation of the SSH protocol suite).

SSH roaming enables a client, in case an SSH connection breaks unexpectedly, to resume it at a later time, provided the server also supports it.

The OpenSSH server doesn't support roaming, but the OpenSSH client supports it (even though it's not documented) and it's enabled by default.

  - CVE-2016-0777     An information leak (memory disclosure) can be exploited     by a rogue SSH server to trick a client into leaking     sensitive data from the client memory, including for     example private keys.

  - CVE-2016-0778     A buffer overflow (leading to file descriptor leak), can     also be exploited by a rogue SSH server, but due to     another bug in the code is possibly not exploitable, and     only under certain conditions (not the default     configuration), when using ProxyCommand, ForwardAgent or     ForwardX11.

This security update completely disables the roaming code in the OpenSSH client.

It is also possible to disable roaming by adding the (undocumented) option 'UseRoaming no' to the global /etc/ssh/ssh_config file, or to the user configuration in ~/.ssh/config, or by passing -oUseRoaming=no on the command line.

Users with passphrase-less private keys, especially in non interactive setups (automated jobs using ssh, scp, rsync+ssh etc.) are advised to update their keys if they have connected to an SSH server they don't trust.

More details about identifying an attack and mitigations will be available in the Qualys Security Advisory.

The Qualys Security team discovered two vulnerabilities in the roaming code of the OpenSSH client (an implementation of the SSH protocol suite).

SSH roaming enables a client, in case an SSH connection breaks unexpectedly, to resume it at a later time, provided the server also supports it.

The OpenSSH server doesn't support roaming, but the OpenSSH client supports it (even though it's not documented) and it's enabled by default.

CVE-2016-0777

An information leak (memory disclosure) can be exploited by a rogue SSH server to trick a client into leaking sensitive data from the client memory, including for example private keys.

CVE-2016-0778

A buffer overflow (leading to file descriptor leak), can also be exploited by a rogue SSH server, but due to another bug in the code is possibly not exploitable, and only under certain conditions (not the default configuration), when using ProxyCommand, ForwardAgent or ForwardX11.

This security update completely disables the roaming code in the OpenSSH client.

It is also possible to disable roaming by adding the (undocumented) option 'UseRoaming no' to the global /etc/ssh/ssh_config file, or to the user configuration in ~/.ssh/config, or by passing -oUseRoaming=no on the command line.

Users with passphrase-less privates keys, especially in non interactive setups (automated jobs using ssh, scp, rsync+ssh etc.) are advised to update their keys if they have connected to an SSH server they don't trust.

More details about identifying an attack and mitigations can be found in the Qualys Security Advisory.

  - -- Yves-Alexis Perez

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

New openssh packages are available for Slackware 13.0, 13.1, 13.37, 14.0, 14.1, and -current to fix security issues.

ID	Name	Product	Family	Severity
106608	OpenSSH 5.4 < 7.1p2 Multiple Vulnerabilities	Nessus	Misc.	high
106499	pfSense < 2.3 Multiple Vulnerabilities (SA-16_01 - SA-16_02)	Nessus	Firewalls	critical
9327	Mac OS X 10.11.x < 10.11.4 Multiple Vulnerabilities	Nessus Network Monitor	Operating System Detection	critical
90097	Mac OS X 10.9.5 / 10.10.5 Multiple Vulnerabilities (Security Update 2016-002)	Nessus	MacOS X Local Security Checks	critical
90096	Mac OS X 10.11.x < 10.11.4 Multiple Vulnerabilities	Nessus	MacOS X Local Security Checks	critical
89505	Fedora 22 : gsi-openssh-6.9p1-7.fc22 (2016-2e89eba0c1)	Nessus	Fedora Local Security Checks	high
88590	AIX OpenSSH Advisory : openssh_advisory7.asc	Nessus	AIX Local Security Checks	medium
88464	Fedora 23 : gsi-openssh-7.1p2-1.fc23 (2016-4556904561)	Nessus	Fedora Local Security Checks	high
88157	openSUSE Security Update : openssh (openSUSE-2016-49)	Nessus	SuSE Local Security Checks	high
88129	openSUSE Security Update : openssh (openSUSE-2016-39)	Nessus	SuSE Local Security Checks	high
88128	openSUSE Security Update : openssh (openSUSE-2016-38)	Nessus	SuSE Local Security Checks	high
87985	GLSA-201601-01 : OpenSSH: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
87972	Amazon Linux AMI : openssh (ALAS-2016-638)	Nessus	Amazon Linux Local Security Checks	high
87963	SUSE SLED11 / SLES11 Security Update : openssh (SUSE-SU-2016:0120-1)	Nessus	SuSE Local Security Checks	high
87962	SUSE SLED11 / SLES11 Security Update : openssh (SUSE-SU-2016:0119-1)	Nessus	SuSE Local Security Checks	high
87961	SUSE SLED12 / SLES12 Security Update : openssh (SUSE-SU-2016:0118-1)	Nessus	SuSE Local Security Checks	high
9055	OpenSSH < 7.1p2 Multiple Vulnerabilities	Nessus Network Monitor	SSH	medium
87939	Ubuntu 14.04 LTS : OpenSSH vulnerabilities (USN-2869-1)	Nessus	Ubuntu Local Security Checks	high
87938	Scientific Linux Security Update : openssh on SL7.x x86_64 (20160114)	Nessus	Scientific Linux Local Security Checks	high
87937	RHEL 7 : openssh (RHSA-2016:0043)	Nessus	Red Hat Local Security Checks	high
87936	Oracle Linux 7 : openssh (ELSA-2016-0043)	Nessus	Oracle Linux Local Security Checks	high
87935	FreeBSD : openssh -- information disclosure (dfe0cdc1-baf2-11e5-863a-b499baebfeaf)	Nessus	FreeBSD Local Security Checks	high
87934	Debian DSA-3446-1 : openssh - security update	Nessus	Debian Local Security Checks	high
87933	Debian DLA-387-1 : openssh security update	Nessus	Debian Local Security Checks	high
87930	CentOS 7 : openssh (CESA-2016:0043)	Nessus	CentOS Local Security Checks	high
87929	Slackware 13.0 / 13.1 / 13.37 / 14.0 / 14.1 / current : openssh (SSA:2016-014-01)	Nessus	Slackware Local Security Checks	high

Detections

Analytics

CVE-2016-0778

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Tenable Plugins

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