# CVE-2023-51079: mvel2 TimeOut error exists in the ParseTools.subCompileExpression method

> An attacker can cause excessive CPU consumption in the MVEL library via crafted expressions, leading to a denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Dec 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-h63j-xqx6-w58r

## What is CVE-2023-51079?

CVE-2023-51079 is a medium-severity denial of service vulnerability in n/a, published on 27 Dec 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A long execution time can occur in the ParseTools.subCompileExpression method in MVEL 2.5.0.Final because of many Java class lookups. NOTE: the vendor disputes this because "the only thing that you could expect is that the parser will take a crazy amount of time to complete its task."

## Which versions are affected by CVE-2023-51079?

2 open source packages ship an affected version, including org.mvel:mvel2. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.mvel:mvel2` | Maven | All versions | None |
| `org.mvel:mvel2` | Maven | All versions | None |

Products: Mvel Mvel.

## How do I fix CVE-2023-51079?

No fix has been published for CVE-2023-51079 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-51079 being exploited?

There is no known exploitation of CVE-2023-51079 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-51079 and fix it if it is affected.

What it is: CVE-2023-51079 is a medium-severity denial of service vulnerability in n/a, published on 27 Dec 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-2023-51079 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.mvel:mvel2 (Maven): affected all versions; no fix listed
- org.mvel:mvel2 (Maven): affected all versions; no fix listed

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-2023-51079/ (Markdown: https://insights.sbomify.com/CVE-2023-51079/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-51079
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-51079
- OSV: https://osv.dev/vulnerability/CVE-2023-51079

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-51079/
Summaries are generated and may contain mistakes; the official description above is the record.