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.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-15091
Reference (s):
- https://github.com/tendermint/tendermint/security/advisories/GHSA-6jqj-f58p-mrw3
- URL: https://github.com/tendermint/tendermint/security/advisories/GHSA-6jqj-f58p-mrw3
- https://github.com/tendermint/tendermint/commit/480b995a31727593f58b361af979054d17d84340
- URL: https://github.com/tendermint/tendermint/commit/480b995a31727593f58b361af979054d17d84340
- https://github.com/tendermint/tendermint/issues/4926