Provide references for CVE-2018-18689.
Where can I find more information about CVE-2018-18689?
References are available at: https://www.foxitsoftware.com/support/security-bulletins.php, https://pdf-insecurity.org/signature/evaluation_2018.html, https://pdf-insecurity.org/signature/signature.html, https://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/.