What’s Vulnerable › Vulnerabilities

CVE-2020-15091: Denial of Service in TenderMint

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-07-02 · updated 2026-06-17
• Weakness: CWE-347

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.

Affected products

• tendermint: from 0.33.0 before 0.33.6 — fixed in 0.33.6

How to fix

Upgrade to a fixed version: tendermint 0.33.6. Check the vendor advisory for mitigations.

References

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

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