X.Org's Latest Security Woes Are Bugs In LibX11, Xserver

The X.Org/X11 Server has been hit by many security vulnerabilities over the past decade as security researchers eye more open-source software. Some of these vulnerabilities date back to even the 80's and 90's given how X11 has built up over time. The X.Org Server security was previously characterized as being even worse than it looks while today the latest vulnerabilities have been made public.

CVE-2020-14344 is now public and covers multiple integer overflows and signed/unsigned comparison issues within the X Input Method implementation in the libX11 library. These issues can lead to heap corruption when handling malformed messages from an input method.

Several patches are now in libX11 Git for addressing these overflows and bad sign comparisons. LibX11 1.6.10 will be released shortly with these fixes.

More details on today's disclosure via the xorg-devel list.

Update: Further security issues are also being made public today... CVE-2020-14347 is public too as a bug in the pixmap data code leading to uninitialized heap memory being leaked to clients. In turn when paired with other flows and running the xorg-server as root could potentially lead to privilege escalation. X.Org Server 1.20.9 to be released soon with this fix, which was discovered as part of the Trend Micro Zero Day Initiative.