USN-4772-1: VNC4 vulnerabilities

Publication date

15 March 2021

Overview

Several security issues were fixed in VNC4.


Packages

  • vnc4 - Virtual network computing

Details

USN-2500-1 addressed CVE-2015-0255 for xorg-server. This update provides
the corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
(CVE-2015-0255)

USN-2726-1 addressed CVE-2015-1283 for Expat. This update provides the
corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
(CVE-2015-1283)

Original advisory details:

Olivier Fourdan discovered that the X.Org X server incorrectly handled
XkbSetGeometry requests resulting in an information leak. An attacker able
to connect to an X server, either locally or remotely, could use this issue
to possibly obtain sensitive information. (CVE-2015-0255)

It was discovered that Expat incorrectly handled malformed XML data. If a
user or application linked against Expat...

USN-2500-1 addressed CVE-2015-0255 for xorg-server. This update provides
the corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
(CVE-2015-0255)

USN-2726-1 addressed CVE-2015-1283 for Expat. This update provides the
corresponding fix for VNC4 on Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
(CVE-2015-1283)

Original advisory details:

Olivier Fourdan discovered that the X.Org X server incorrectly handled
XkbSetGeometry requests resulting in an information leak. An attacker able
to connect to an X server, either locally or remotely, could use this issue
to possibly obtain sensitive information. (CVE-2015-0255)

It was discovered that Expat incorrectly handled malformed XML data. If a
user or application linked against Expat were tricked into opening a
crafted XML file, an attacker could cause a denial of service, or possibly
execute arbitrary code. (CVE-2015-1283)


Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
16.04 xenial xvnc4viewer –  4.1.1+xorg4.3.0-37.3ubuntu2.1+esm1  
vnc4server –  4.1.1+xorg4.3.0-37.3ubuntu2.1+esm1  
14.04 trusty xvnc4viewer –  4.1.1+xorg4.3.0-37ubuntu5.0.2+esm1  
vnc4server –  4.1.1+xorg4.3.0-37ubuntu5.0.2+esm1  

Reduce your security exposure

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