Several security issues were fixed in LibVNCServer.
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)
29 September 2014
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in LibVNCServer.
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)
The problem can be corrected by updating your system to the following package versions:
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.