Improper Verification of Cryptographic Signature
Tendermint is a high-performance blockchain consensus engine for Byzantine fault tolerant applications. Versions prior to 0.28.0 contain a potential attack via Improper Verification of Cryptographic Signature, affecting anyone using the tendermint-light-client and related packages to perform light client verification (e.g. IBC-rs, Hermes). The light client does not check that the chain IDs of the trusted and untrusted headers match, resulting in a possible attack vector where someone who finds a header from an untrusted chain that satisfies all other verification conditions (e.g. enough overlapping validator signatures) could fool a light client. The attack vector is currently theoretical, and no proof-of-concept exists yet to exploit it on live networks. This issue is patched in version 0.28.0. There are no workarounds.
CWE-347 - Improper Verification of Cryptographic Signature
A cryptographic protocol is meant to ensure that services are provided in a secure manner. An application with absent or improper verification of cryptographic signatures allows malicious users to feed false messages to valid users or to disclose sensitive data, subverting the goals of the protocol. This can lead to security failures such as false authentication, account hijacking, and privilege escalation.