USN-3500-1: libXfont vulnerability

29 November 2017

libxfont, libxfont1, libxfont2 vulnerability


  • libxfont - X11 font rasterisation library
  • libxfont1 - X11 font rasterisation library
  • libxfont2 - X11 font rasterisation library


It was discovered that libXfont incorrectly followed symlinks when opening
font files. A local unprivileged user could use this issue to cause the X
server to access arbitrary files, including special device files.

Update instructions

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

Ubuntu 17.10
Ubuntu 17.04
Ubuntu 16.04
Ubuntu 14.04

After a standard system update you need to reboot your computer to make
all the necessary changes.