RHEL 7 : tigervnc and fltk (RHSA-2017:2000)

critical Nessus Plugin ID 102109

Synopsis

The remote Red Hat host is missing one or more security updates.

Description

An update for tigervnc and fltk is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) 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 which allows users to connect to other desktops running a VNC server.

FLTK (pronounced 'fulltick') is a cross-platform C++ GUI toolkit. It provides modern GUI functionality without the bloat, and supports 3D graphics via OpenGL and its built-in GLUT emulation.

The following packages have been upgraded to a later upstream version:
tigervnc (1.8.0), fltk (1.3.4). (BZ#1388620, BZ#1413598)

Security Fix(es) :

* A denial of service flaw was found in the TigerVNC's Xvnc server. A remote unauthenticated attacker could use this flaw to make Xvnc crash by terminating the TLS handshake process early. (CVE-2016-10207)

* A double free flaw was found in the way TigerVNC handled ClientFence messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientFence messages, resulting in denial of service. (CVE-2017-7393)

* A missing input sanitization flaw was found in the way TigerVNC handled credentials. A remote unauthenticated attacker could use this flaw to make Xvnc crash by sending specially crafted usernames, resulting in denial of service. (CVE-2017-7394)

* An integer overflow flaw was found in the way TigerVNC handled ClientCutText messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientCutText messages, resulting in denial of service.
(CVE-2017-7395)

* A buffer overflow flaw, leading to memory corruption, was found in TigerVNC viewer. A remote malicious VNC server could use this flaw to crash the client vncviewer process resulting in denial of service.
(CVE-2017-5581)

* A memory leak flaw was found in the way TigerVNC handled termination of VeNCrypt connections. A remote unauthenticated attacker could repeatedly send connection requests to the Xvnc server, causing it to consume large amounts of memory resources over time, and ultimately leading to a denial of service due to memory exhaustion.
(CVE-2017-7392)

* A memory leak flaw was found in the way TigerVNC handled client connections. A remote unauthenticated attacker could repeatedly send connection requests to the Xvnc server, causing it to consume large amounts of memory resources over time, and ultimately leading to a denial of service due to memory exhaustion. (CVE-2017-7396)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.4 Release Notes linked from the References section.

Solution

Update the affected packages.

See Also

http://www.nessus.org/u?3395ff0b

https://access.redhat.com/errata/RHSA-2017:2000

https://access.redhat.com/security/cve/cve-2016-10207

https://access.redhat.com/security/cve/cve-2017-5581

https://access.redhat.com/security/cve/cve-2017-7392

https://access.redhat.com/security/cve/cve-2017-7393

https://access.redhat.com/security/cve/cve-2017-7394

https://access.redhat.com/security/cve/cve-2017-7395

https://access.redhat.com/security/cve/cve-2017-7396

Plugin Details

Severity: Critical

ID: 102109

File Name: redhat-RHSA-2017-2000.nasl

Version: 3.12

Type: local

Agent: unix

Published: 8/2/2017

Updated: 10/24/2019

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:tigervnc, p-cpe:/a:redhat:enterprise_linux:tigervnc-debuginfo, p-cpe:/a:redhat:enterprise_linux:tigervnc-icons, p-cpe:/a:redhat:enterprise_linux:tigervnc-license, p-cpe:/a:redhat:enterprise_linux:tigervnc-server, p-cpe:/a:redhat:enterprise_linux:tigervnc-server-applet, p-cpe:/a:redhat:enterprise_linux:tigervnc-server-minimal, p-cpe:/a:redhat:enterprise_linux:tigervnc-server-module, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:7.4, cpe:/o:redhat:enterprise_linux:7.5, cpe:/o:redhat:enterprise_linux:7.6, cpe:/o:redhat:enterprise_linux:7.7, p-cpe:/a:redhat:enterprise_linux:fltk, p-cpe:/a:redhat:enterprise_linux:fltk-debuginfo, p-cpe:/a:redhat:enterprise_linux:fltk-devel, p-cpe:/a:redhat:enterprise_linux:fltk-fluid, p-cpe:/a:redhat:enterprise_linux:fltk-static

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 8/1/2017

Vulnerability Publication Date: 2/28/2017

Reference Information

CVE: CVE-2016-10207, CVE-2017-5581, CVE-2017-7392, CVE-2017-7393, CVE-2017-7394, CVE-2017-7395, CVE-2017-7396

RHSA: 2017:2000