# CVE-2023-33964: mx-chain-go does not treat invalid transaction with wrong username correctly

> An invalid transaction with a wrong username causes the MultiversX metachain to stop notarizing blocks, requiring a binary upgrade to restore functionality.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 May 2023
- **Updated:** 9 Jan 2025
- **Also known as:** GHSA-7xpv-4pm9-xch2, GO-2023-1806

## What is CVE-2023-33964?

CVE-2023-33964 is a high-severity denial of service vulnerability in multiversx mx-chain-go, published on 31 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mx-chain-go is an implementation of the MultiversX blockchain protocol written in the Go language. Metachain cannot process a cross-shard miniblock. Prior to version 1.4.16, an invalid transaction with the wrong username on metachain is not treated correctly on the metachain transaction processor. This is strictly a processing issue that could have happened on MultiversX chain. If an error like this had occurred, the metachain would have stopped notarizing blocks from the shard chains. The resuming of notarization is possible only after applying a patched binary version. A patch in version 1.4.16 introduces `processIfTxErrorCrossShard` for the metachain transaction processor. There are no known workarounds for this issue.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-33964?

3 open source packages ship an affected version, including github.com/multiversx/mx-chain-go. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/multiversx/mx-chain-go` | Go | All versions | 1.4.16 |
| `github.com/multiversx/mx-chain-go` | Go | All versions | 1.4.16 |
| `github.com/multiversx/mx-chain-go` | Go | All versions | 1.4.16 |

Products: Multiversx Mx-Chain-Go.

## How do I fix CVE-2023-33964?

Upgrade github.com/multiversx/mx-chain-go to 1.4.16 or later.

## Is CVE-2023-33964 being exploited?

There is no known exploitation of CVE-2023-33964 in the wild and no public exploit code.

## Other vulnerabilities in multiversx mx-chain-go

- [CVE-2023-34458](https://insights.sbomify.com/CVE-2023-34458/): mx-chain-go's relayed transactions always increment nonce (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-33964 and fix it if it is affected.

What it is: CVE-2023-33964 is a high-severity denial of service vulnerability in multiversx mx-chain-go, published on 31 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-33964 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/multiversx/mx-chain-go (Go): affected all versions; fixed in 1.4.16
- github.com/multiversx/mx-chain-go (Go): affected all versions; fixed in 1.4.16
- github.com/multiversx/mx-chain-go (Go): affected all versions; fixed in 1.4.16

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-33964/ (Markdown: https://insights.sbomify.com/CVE-2023-33964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-33964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-33964
- OSV: https://osv.dev/vulnerability/CVE-2023-33964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-33964/
Summaries are generated and may contain mistakes; the official description above is the record.