Skip to content
Fencer Intel
high —

GHSA-6jrf-4jv4-r9mw json

tendermint-rs's Light Client Verifier allows malicious validators to spoof votes from other validators

published last yr. modified last yr.

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

Name: ISA-2025-003: Malicious validator can spoof votes from other validators Component: tendermint-rs Criticality: High (Catastrophic Impact; Rare Likelihood per [ACMv1.2](https://github.com/interchainio/security/blob/main/resources/CLASSIFICATION_MATRIX.md)) Affected versions: <= v0.40.2 Affected users: Everyone

### Description

tendermint-rs contains a critical vulnerability in its light client implementation due to insecure handling of corrupted validator sets. Because it doesn't check that the validator address is correctly derived from the validator's public key when counting votes, it is possible to spoof votes from other validators. The result is being able to construct the malicious block and cheat the light client. The light client will accept such a block, seemingly signed by 2/3+ majority.

### Patches

The new tendermint-rs release [v0.40.3](https://github.com/informalsystems/tendermint-rs/releases/tag/v0.40.3) fixes this issue.

Unreleased code in the main branch is patched as well.

### Workarounds

There are no known workarounds for this issue.

### Timeline

* March 12, 2025, 13:41pm PST: Issue reported * March 12, 2025, 03:00am PST: Core team completes validation of issue

This issue was reported by Felix Wilhelm from [Asymmetric Research](https://www.asymmetric.re/).

Patch / fix

  • crates.io tendermint-light-client-verifier 0.40.3

Is GHSA-6jrf-4jv4-r9mw in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Affected packages

ecosystem package affected fixed in
crates.io tendermint-light-client-verifier
<0.40.3
0.40.3

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.