GHSA-23qp-3c2m-xx6w wasmvm: Malicious smart contract can crash the chain

Not scored Published 4 Feb 2025

A malicious smart contract can crash the blockchain network via a bug in the wasmvm library, requiring an upgrade to patched versions.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is GHSA-23qp-3c2m-xx6w?

GHSA-23qp-3c2m-xx6w is a denial of service vulnerability in github.com/CosmWasm/wasmvm, published on 4 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

CWA-2025-001

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 crash the chain. The underlying bug that causes this is present on both permissioned and premissionless chains, but it can only be triggered reliably with a malicious contract, so permissioned chains are much less likely 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:

Check the current wasmvm version: go list -m github.com/CosmWasm/wasmvm
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.
If you use the static libraries libwasmvm_muslc.aarch64.a/libwasmvm_muslc.x86_64.a, update them accordingly.
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.
Follow your regular practices to deploy chain upgrades.

While the fix for this issue is not consensus breaking, the patch contains another consensus breaking fix 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

2024-11-25: Confio receives a report through the Cosmos bug bounty program maintained by Amulet.
2024-11-28: Confio security contributors confirm the report.
2024-11-28: Confio developed the patch internally.
2025-02-04: Patch gets released.

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

Which versions are affected by GHSA-23qp-3c2m-xx6w?

12 open source packages ship an affected version, including github.com/CosmWasm/wasmvm/v2 and github.com/CosmWasm/wasmvm.

Package	Affected	Fixed in
`github.com/CosmWasm/wasmvm/v2` Go	All versions	`2.0.6`
`github.com/CosmWasm/wasmvm/v2` Go	All versions	`2.1.5`
`github.com/CosmWasm/wasmvm/v2` Go	All versions	`2.2.2`
`github.com/CosmWasm/wasmvm/v2` Go	From `2.0.0`	`2.0.6`
`github.com/CosmWasm/wasmvm/v2` Go	From `2.0.0`	`2.0.6`
`github.com/CosmWasm/wasmvm/v2` Go	From `2.1.0`	`2.1.5`

6 more packages

`github.com/CosmWasm/wasmvm/v2` Go	From `2.1.0`	`2.1.5`
`github.com/CosmWasm/wasmvm/v2` Go	From `2.2.0`	`2.2.2`
`github.com/CosmWasm/wasmvm/v2` Go	From `2.2.0`	`2.2.2`
`github.com/CosmWasm/wasmvm` Go	All versions	`1.5.8`
`github.com/CosmWasm/wasmvm` Go	All versions	`1.5.8`
`github.com/CosmWasm/wasmvm` Go	All versions	`1.5.8`

How do I fix GHSA-23qp-3c2m-xx6w?

Upgrade github.com/CosmWasm/wasmvm/v2 to a fixed version for your release line: 2.0.6, 2.1.5 or 2.2.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is GHSA-23qp-3c2m-xx6w being exploited?

There is no known exploitation of GHSA-23qp-3c2m-xx6w in the wild and no public exploit code.

Sources

Also known as GO-2025-3448.