CVE-2023-35936

Pandoc is a Haskell library for converting from one markup format to
another, and a command-line tool that uses this library. Starting in
version 1.13 and prior to version 3.1.4, Pandoc is susceptible to an
arbitrary file write vulnerability, which can be triggered by providing a
specially crafted image element in the input when generating files using
the --extract-media option or outputting to PDF format. This
vulnerability allows an attacker to create or overwrite arbitrary files on
the system ,depending on the privileges of the process running pandoc. It
only affects systems that pass untrusted user input to pandoc and allow
pandoc to be used to produce a PDF or with the --extract-media option.
The fix is to unescape the percent-encoding prior to checking that the
resource is not above the working directory, and prior to extracting the
extension. Some code for checking that the path is below the working
directory was flawed in a similar way and has also been fixed. Note that
the --sandbox option, which only affects IO done by readers and writers
themselves, does not block this vulnerability. The vulnerability is patched
in pandoc 3.1.4. As a workaround, audit the pandoc command and disallow PDF
output and the --extract-media option.