VNC servers created with x11vnc accept insecure protocol types, even when the server does not offer it, resulting in the possibility of unauthorized access to the server.
| Package | Arch | Vulnerable | Unaffected |
|---|---|---|---|
| x11-misc/x11vnc | * | < 0.8.1 | >= 0.8.1 |
x11vnc provides VNC servers for X displays.
x11vnc includes vulnerable LibVNCServer code, which fails to properly validate protocol types effectively letting users decide what protocol to use, such as "Type 1 - None" (GLSA-200608-05). x11vnc will accept this security type, even if it is not offered by the server.
An attacker could exploit this vulnerability to gain unauthorized access with the privileges of the user running the VNC server.
There is no known workaround at this time.
All x11vnc users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=x11-misc/x11vnc-0.8.1"