Ubuntu Security Notice USN-2365-1
29th September, 2014
libvncserver vulnerabilities
A security issue affects these releases of Ubuntu and its
derivatives:
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS
Summary
Several security issues were fixed in LibVNCServer.
Software description
- libvncserver
– vnc server library
Details
Nicolas Ruff discovered that LibVNCServer incorrectly handled memory when
being advertised large screen sizes by the server. If a user were tricked
into connecting to a malicious server, an attacker could use this issue to
cause a denial of service, or possibly execute arbitrary code.
(CVE-2014-6051, CVE-2014-6052)
Nicolas Ruff discovered that LibVNCServer incorrectly handled large
ClientCutText messages. A remote attacker could use this issue to cause a
server to crash, resulting in a denial of service. (CVE-2014-6053)
Nicolas Ruff discovered that LibVNCServer incorrectly handled zero scaling
factor values. A remote attacker could use this issue to cause a server to
crash, resulting in a denial of service. (CVE-2014-6054)
Nicolas Ruff discovered that LibVNCServer incorrectly handled memory in the
file transfer feature. A remote attacker could use this issue to cause a
server to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2014-6055)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 14.04 LTS:
-
libvncserver0
0.9.9+dfsg-1ubuntu1.1
- Ubuntu 12.04 LTS:
-
libvncserver0
0.9.8.2-2ubuntu1.1
To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.