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wasmvm: Malicious smart contract can slow down block production

Moderate severity GitHub Reviewed Published Feb 4, 2025 in CosmWasm/wasmvm • Updated Jul 9, 2025

Package

cargo cosmwasm-vm (Rust)

Affected versions

= 2.2.0
>= 2.1.0, < 2.1.6
>= 2.0.0, < 2.0.9
< 1.5.10

Patched versions

2.2.1
2.1.6
2.0.9
1.5.10
gomod github.com/CosmWasm/wasmvm (Go)
< 0.0.0-20250204093451-1f4db20199b8
>= 0.1.0, <= 1.5.7
>= 1.5.8-0, < 1.5.8-0.20250204093451-1f4db20199b8
0.0.0-20250204093451-1f4db20199b8
1.5.8
1.5.8-0.20250204093451-1f4db20199b8
gomod github.com/CosmWasm/wasmvm/v2 (Go)
>= 2.2.0, < 2.2.2
>= 2.1.0, < 2.1.5
< 2.0.0-20250204103256-d62c3b826a9d
>= 2.0.0, <= 2.0.5
>= 2.0.6-0, < 2.0.6-0.20250204103256-d62c3b826a9d
2.2.2
2.1.5
2.0.0-20250204103256-d62c3b826a9d
2.0.6
2.0.6-0.20250204103256-d62c3b826a9d

Description

CWA-2025-002

Severity

Medium (Moderate + Likely)1

Affected versions:

  • wasmvm >= 2.2.0, < 2.2.2
  • wasmvm >= 2.1.0, < 2.1.5
  • wasmvm >= 2.0.0, < 2.0.6
  • wasmvm < 1.5.8

Patched versions:

  • wasmvm 1.5.8, 2.0.6, 2.1.5, 2.2.2

Description of the bug

The vulnerability can be used to slow down block production. The attack requires a malicious contract,
so permissioned chains are unlikely to be affected.

(We'll add more detail once chains had a chance to upgrade.)

Patch

Applying the patch

The patch will be shipped in releases of wasmvm. You can update more or less as follows:

  1. Check the current wasmvm version: go list -m github.com/CosmWasm/wasmvm
  2. Bump the github.com/CosmWasm/wasmvm dependency in your go.mod to one of the patched version
    depending on which minor version you are on; go mod tidy; commit.
  3. If you use the static libraries libwasmvm_muslc.aarch64.a/libwasmvm_muslc.x86_64.a, update them accordingly.
  4. Check the updated wasmvm version: go list -m github.com/CosmWasm/wasmvm and ensure you see 1.5.8, 2.0.6, 2.1.5 or 2.2.2.
  5. Follow your regular practices to deploy chain upgrades.

The patch is consensus breaking and requires a coordinated upgrade.

Acknowledgement

This issue was found by meadow101 who reported it to the Cosmos Bug Bounty Program on HackerOne.

If you believe you have found a bug in the Interchain Stack or would like to contribute to the
program by reporting a bug, please see https://hackerone.com/cosmos.

Timeline

  • 2024-11-24: Confio receives a report through the Cosmos bug bounty program maintained by Amulet.
  • 2024-12-20: Confio security contributors confirm the report.
  • 2024-01-27: Confio developed the patch internally.
  • 2025-02-04: Patch gets released.

References

Footnotes

  1. following Amulet's Severity Classification Framework ACMv1.2: https://github.com/interchainio/security/blob/0295254e8645301ccb606d46108a45cede0a73e0/resources/CLASSIFICATION_MATRIX.md ↩

@chipshort chipshort published to CosmWasm/wasmvm Feb 4, 2025
Published to the GitHub Advisory Database Feb 4, 2025
Reviewed Feb 4, 2025
Last updated Jul 9, 2025

Severity

Moderate

EPSS score

Weaknesses

No CWEs

CVE ID

No known CVE

GHSA ID

GHSA-mx2j-7cmv-353c

Source code

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