CVE-2020-15091 Denial of Service in TenderMint

What is CVE-2020-15091?

CVE-2020-15091 is a medium-severity denial of service vulnerability in tendermint, published on 2 Jul 2020. Any signed-in user can exploit it over the network, with no action from the victim.

Official 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.

Weakness: CWE-347

Which versions are affected by CVE-2020-15091?

3 open source packages ship an affected version, including github.com/tendermint/tendermint. It affects 1 product.

Products include Tendermint Tendermint.

How do I fix CVE-2020-15091?

Upgrade github.com/tendermint/tendermint to a fixed version for your release line: 0.33.6 or 0.34.0-dev1.0.20200702134149-480b995a3172.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2020-15091 being exploited?

There is no known exploitation of CVE-2020-15091 in the wild and no public exploit code.

Other vulnerabilities in tendermint

• CVE-2019-25072 Uncontrolled resource consumption in github.com/tendermint/tendermint High 7.5
• CVE-2021-21271 Denial of service in TenderMint Core Medium 6.5
• CVE-2020-5303 Denial of service in Tendermint Low 3.1

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-6jqj-f58p-mrw3, GO-2021-0090.