Denial of Service in TenderMint

Vulnerability Description

TenderMint from version 0.33.0 and before version 0.33.6 allows block proposers to include signatures for the wrong block. This may happen naturally if you start a network, have it run for some time and restart it (**without changing chainID**). A malicious block proposer (even with a minimal amount of stake) can use this vulnerability to completely halt the network. This issue is fixed in Tendermint 0.33.6 which checks all the signatures are for the block with 2/3+ majority before creating a commit.

References

• https://github.com/tendermint/tendermint/security/advisories/GHSA-6jqj-f58p-mrw3
• https://github.com/tendermint/tendermint/issues/4926
• https://github.com/tendermint/tendermint/commit/480b995a31727593f58b361af979054d17d84340