Message Signature Bypass in openpgp

Versions of openpgp prior to 4.2.0 are vulnerable to Message Signature Bypass. The package fails to verify that a message signature is of type text. This allows an attacker to to construct a message with a signature type that only verifies subpackets without additional input (such as standalone or timestamp). For example, an attacker that captures a standalone signature packet from a victim can construct arbitrary signed messages that would be verified correctly.

Recommendation

Upgrade to version 4.2.0 or later. If you are upgrading from a version <4.0.0 it is highly recommended to read the High-Level API Changes section of the openpgp 4.0.0 release: https://github.com/openpgpjs/openpgpjs/releases/tag/v4.0.0