CVE-2018-18688

https://notcve.org/view.php?id=CVE-2018-18688

07 Jan 2021 — The Portable Document Format (PDF) specification does not provide any information regarding the concrete procedure of how to validate signatures. Consequently, an Incremental Saving vulnerability exists in multiple products. When an attacker uses the Incremental Saving feature to add pages or annotations, Body Updates are displayed to the user without any action by the signature-validation logic. This affects Foxit Reader before 9.4 and PhantomPDF before 8.3.9 and 9.x before 9.4. It also affects LibreOffice... • https://pdf-insecurity.org/signature/evaluation_2018.html • CWE-347: Improper Verification of Cryptographic Signature •