Roman Fiedler reported that missing length validation in various
functions provided by libx11, the X11 client-side library, allow
to inject X11 protocol commands on X clients, leading to
authentication bypass, denial of service or potentially the
execution of arbitrary code.
For the stable distribution (buster), this problem has been fixed in
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 Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/
Mailing list: [email protected]
Debian Security Advisory DSA-4920-1 [email protected]
https://www.debian.org/security/ Salvatore Bonaccorso
May 24, 2021 https://www.debian.org/security/faq