Integer overflow in TigerVNC allows remote VNC servers to cause a denial of service (crash) and possibly execute arbitrary code via vectors related to screen size handling, which triggers a heap-based buffer overflow, a similar issue to CVE-2014-6051.

The remote Redhat Enterprise Linux 6 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - tigervnc: NULL pointer dereference flaw in XRegion (CVE-2014-8241)

  - Integer overflow in TigerVNC allows remote VNC servers to cause a denial of service (crash) and possibly     execute arbitrary code via vectors related to screen size handling, which triggers a heap-based buffer     overflow, a similar issue to CVE-2014-6051. (CVE-2014-8240)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

The remote Redhat Enterprise Linux 5 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - tigervnc: NULL pointer dereference flaw in XRegion (CVE-2014-8241)

  - Integer overflow in TigerVNC allows remote VNC servers to cause a denial of service (crash) and possibly     execute arbitrary code via vectors related to screen size handling, which triggers a heap-based buffer     overflow, a similar issue to CVE-2014-6051. (CVE-2014-8240)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

The remote host is affected by the vulnerability described in GLSA-201612-36 (TigerVNC: Integer overflow)

    TigerVNC is impacted by the same vulnerability as found in       CVE-2014-6051. An integer overflow, leading to a heap-based buffer       overflow, was found in the way screen sizes were handled.
  Impact :

    A remote attacker, utilizing a malicious VNC server, could execute       arbitrary code with the privileges of the user running the client, or       cause a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240)

A NULL pointer dereference flaw was found in TigerVNC's XRegion. A malicious VNC server could use this flaw to cause a client to crash.
(CVE-2014-8241)

The tigervnc packages have been upgraded to upstream version 1.3.1, which provides a number of bug fixes and enhancements over the previous version.

This update also fixes the following bug :

  - The position of the mouse cursor in the VNC session was     not correctly communicated to the VNC viewer, resulting     in cursor misplacement. The method of displaying the     remote cursor has been changed, and cursor movements on     the VNC server are now accurately reflected on the VNC     client.

An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client.

A NULL pointer dereference flaw was found in TigerVNC's XRegion. A malicious VNC server could use this flaw to cause a client to crash.

Updated tigervnc packages that fix two security issues, several bugs, and add various enhancements 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.

Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients. The tigervnc packages contain a client which allows users to connect to other desktops running a VNC server.

An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240)

A NULL pointer dereference flaw was found in TigerVNC's XRegion. A malicious VNC server could use this flaw to cause a client to crash.
(CVE-2014-8241)

The tigervnc packages have been upgraded to upstream version 1.3.1, which provides a number of bug fixes and enhancements over the previous version. (BZ#1199453)

This update also fixes the following bug :

* The position of the mouse cursor in the VNC session was not correctly communicated to the VNC viewer, resulting in cursor misplacement. The method of displaying the remote cursor has been changed, and cursor movements on the VNC server are now accurately reflected on the VNC client. (BZ#1100661)

All tigervnc users are advised to upgrade to these updated packages, which correct these issues and add these enhancements.

From Red Hat Security Advisory 2015:2233 :

Updated tigervnc packages that fix two security issues, several bugs, and add various enhancements 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.

Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients. The tigervnc packages contain a client which allows users to connect to other desktops running a VNC server.

An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240)

A NULL pointer dereference flaw was found in TigerVNC's XRegion. A malicious VNC server could use this flaw to cause a client to crash.
(CVE-2014-8241)

The tigervnc packages have been upgraded to upstream version 1.3.1, which provides a number of bug fixes and enhancements over the previous version. (BZ#1199453)

This update also fixes the following bug :

* The position of the mouse cursor in the VNC session was not correctly communicated to the VNC viewer, resulting in cursor misplacement. The method of displaying the remote cursor has been changed, and cursor movements on the VNC server are now accurately reflected on the VNC client. (BZ#1100661)

All tigervnc users are advised to upgrade to these updated packages, which correct these issues and add these enhancements.

This update for tigervnc provides the following fixes :

  - Fixed integer overflow flaw, leading to a heap-based     buffer overflow in screen size handling. (CVE-2014-8240)

  - Send correctly keys that don't type any characters, such     as CTRL+Space. (bnc#906922)

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.

ID	Name	Product	Family	Severity
198446	RHEL 6 : vnc (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
198336	RHEL 5 : vnc (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
95739	GLSA-201612-36 : TigerVNC: Integer overflow	Nessus	Gentoo Local Security Checks	high
87576	Scientific Linux Security Update : tigervnc on SL7.x x86_64 (20151119)	Nessus	Scientific Linux Local Security Checks	critical
87349	Amazon Linux AMI : tigervnc (ALAS-2015-623)	Nessus	Amazon Linux Local Security Checks	critical
87144	CentOS 7 : tigervnc (CESA-2015:2233)	Nessus	CentOS Local Security Checks	critical
87093	Oracle Linux 7 : tigervnc (ELSA-2015-2233)	Nessus	Oracle Linux Local Security Checks	critical
86976	RHEL 7 : tigervnc (RHSA-2015:2233)	Nessus	Red Hat Local Security Checks	critical
83649	SUSE SLED12 / SLES12 Security Update : tigervnc (SUSE-SU-2014:1592-1)	Nessus	SuSE Local Security Checks	high

Detections

Analytics

CVE-2014-8240

critical

Tenable Plugins

critical

critical

high

critical

critical

critical

critical

critical

high