CVE-2024-28123

In the WASMI Interpreter, an Out-of-bounds Buffer Write will arise arise if the host calls or resumes a Wasm function with more parameters than the default limit (128), as it will surpass the stack value. This doesn’t affect calls from Wasm to Wasm, only from host to Wasm.

Mitigations

If you are using wasmi betwen version 0.15.0 and 0.31.0, please update it to the 0.31.1 patch release that we just published.

Workarounds

Ensure no more than 128 parameters can be pass in a call from the host to a Wasm function.

References

Patch PR:

Special thanks

Special thanks to Stellar Development Foundation for reporting this security vulnerability.

After conducting an analysis of the dependent Polkadot systems of wasmi: Pallet Contracts, Parity Signer, and Smoldot, we have found that none on those systems have been affected by the issue as they are calling host to Wasm function with a small limited amount of parameters always.

A write operation targets a memory location beyond the intended buffer boundary. Typical impact: memory corruption, crash, or arbitrary code execution.

CVE-2024-28123 has a CVSS score of 7.3 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.31.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2024-28123? CVE-2024-28123 is a high-severity out-of-bounds write vulnerability in wasmi (rust), affecting versions >= 0.15.0, <= 0.31.0. It is fixed in 0.31.1. A write operation targets a memory location beyond the intended buffer boundary.
2. How severe is CVE-2024-28123? CVE-2024-28123 has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of wasmi are affected by CVE-2024-28123? wasmi (rust) versions >= 0.15.0, <= 0.31.0 is affected.
4. Is there a fix for CVE-2024-28123? Yes. CVE-2024-28123 is fixed in 0.31.1. Upgrade to this version or later.
5. Is CVE-2024-28123 exploitable, and should I be worried? Whether CVE-2024-28123 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-28123 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-28123? Upgrade wasmi to 0.31.1 or later.