CVE-2023-3823

In PHP versions 8.0.* before 8.0.30, 8.1.* before 8.1.22, and 8.2.* before
8.2.8 various XML functions rely on libxml global state to track
configuration variables, like whether external entities are loaded. This
state is assumed to be unchanged unless the user explicitly changes it by
calling appropriate function. However, since the state is process-global,
other modules - such as ImageMagick - may also use this library within the
same process, and change that global state for their internal purposes, and
leave it in a state where external entities loading is enabled. This can
lead to the situation where external XML is parsed with external entities
loaded, which can lead to disclosure of any local files accessible to PHP.
This vulnerable state may persist in the same process across many requests,
until the process is shut down.

Bugs

• <https://bugs.launchpad.net/ubuntu/+source/php7.4/+bug/2054511&gt;

Notes