Vulnerability in Foxit PDF Editor

Foxit PDF Editor and Reader before 2025.2.1 allow signature spoofing via OCG. When Optional Content Groups (OCG) are supported, the state property of an OCG is runtime-only and not included in the digital signature computation buffer. An attacker can leverage JavaScript or PDF triggers to dynamically change the visibility of OCG content after signing (Post-Sign), allowing the visual content of a signed PDF to be modified without invalidating the signature. This may result in a mismatch between the signed content and what the signer or verifier sees, undermining the trustworthiness of the digital signature. The fixed versions are 2025.2.1, 14.0.1, and 13.2.1.