# CVE-2021-41862: Expression injection in AviatorScript

> Attackers can execute arbitrary code by submitting malicious expressions encoded with BCEL to the AviatorScript library.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-xpv2-8ppj-79hh

## What is CVE-2021-41862?

CVE-2021-41862 is a critical code injection vulnerability in n/a, published on 1 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

AviatorScript through 5.2.7 allows code execution via an expression that is encoded with Byte Code Engineering Library (BCEL).

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2021-41862?

2 open source packages ship an affected version, including com.googlecode.aviator:aviator. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.googlecode.aviator:aviator` | Maven | From 5.2.1 to 5.2.7 | None |
| `com.googlecode.aviator:aviator` | Maven | From 5.2.1 to 5.2.7 | None |

Products: Aviatorscript Project Aviatorscript.

## How do I fix CVE-2021-41862?

No fix has been published for CVE-2021-41862 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41862 being exploited?

There is no known exploitation of CVE-2021-41862 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41862 and fix it if it is affected.

What it is: CVE-2021-41862 is a critical code injection vulnerability in n/a, published on 1 Oct 2021. 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-2021-41862 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.googlecode.aviator:aviator (Maven): affected from 5.2.1 up to 5.2.7; no fix listed
- com.googlecode.aviator:aviator (Maven): affected from 5.2.1 up to 5.2.7; 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-2021-41862/ (Markdown: https://insights.sbomify.com/CVE-2021-41862/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41862
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41862
- OSV: https://osv.dev/vulnerability/CVE-2021-41862

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41862/
Summaries are generated and may contain mistakes; the official description above is the record.