Roman Fiedler found that libX11, the X11 protocol client library, was
vulnerable to protocol command injection due to insufficient validation
of arguments to some functions.
For Debian 9 stretch, this problem has been fixed in version
We recommend that you upgrade your libx11 packages.
For the detailed security status of libx11 please refer to
its security tracker page at:
Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS
Debian LTS Advisory DLA-2666-1 [email protected]
https://www.debian.org/lts/security/ Emilio Pozuelo Monfort
May 24, 2021 https://wiki.debian.org/LTS
Version : 2:1.6.4-3+deb9u4