GHSA-6jrf-4jv4-r9mw
tendermint-rs's Light Client Verifier allows malicious validators to spoof votes from other validators
GHSA-6jrf-4jv4-r9mw is a high vulnerability (CVSS 8.2) in tendermint-light-client-verifier, published April 9, 2025. No source lists public exploit code. Fixed in tendermint-light-client-verifier 0.40.3.
- Severity
- 8.2 HighCVSS 4.0, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
0.40.3tendermint-light-client-verifier
Description
Name: ISA-2025-003: Malicious validator can spoof votes from other validators Component: tendermint-rs Criticality: High (Catastrophic Impact; Rare Likelihood per ACMv1.2) 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 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Affected packages
| Package | Affected | Fixed |
|---|---|---|
tendermint-light-client-verifiercrates.io | before 0.40.3 | 0.40.3 |
What each source reports
GitHub Advisories Score used
tendermint-rs's Light Client Verifier allows malicious validators to spoof votes from other validators
Name: ISA-2025-003: Malicious validator can spoof votes from other validators Component: tendermint-rs Criticality: High (Catastrophic Impact; Rare Likelihood per ACMv1.2) 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 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.
- Record
GHSA-6jrf-4jv4-r9mw- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
tendermint-rs's Light Client Verifier allows malicious validators to spoof votes from other validators
Name: ISA-2025-003: Malicious validator can spoof votes from other validators Component: tendermint-rs Criticality: High (Catastrophic Impact; Rare Likelihood per ACMv1.2) 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 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.
- Record
GHSA-6jrf-4jv4-r9mw- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-863
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.