# CVE-2021-46703: Code injection in RazorEngine

> Attackers can execute arbitrary .NET code via controlled template contents in the unsupported IsolatedRazorEngine component.

- **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:** 6 Mar 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-ph3v-2hq5-5qfq

## What is CVE-2021-46703?

CVE-2021-46703 is a critical code injection vulnerability in n/a, published on 6 Mar 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the IsolatedRazorEngine component of Antaris RazorEngine through 4.5.1-alpha001, an attacker can execute arbitrary .NET code in a sandboxed environment (if users can externally control template contents). NOTE: This vulnerability only affects products that are no longer supported by the maintainer

## Which versions are affected by CVE-2021-46703?

2 open source packages ship an affected version, including RazorEngine. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `RazorEngine` | NuGet | All versions to 4.5.1-alpha001 | None |
| `RazorEngine` | NuGet | All versions to 4.5.1-alpha001 | None |

Products: Razorengine Project Razorengine.

## How do I fix CVE-2021-46703?

No fix has been published for CVE-2021-46703 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-46703 being exploited?

There is no known exploitation of CVE-2021-46703 in the wild and no public exploit code.

Public exploit code:

- Simple payload builder (github_poc): https://github.com/BenEdridge/CVE-2021-46703

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-46703 and fix it if it is affected.

What it is: CVE-2021-46703 is a critical code injection vulnerability in n/a, published on 6 Mar 2022. 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-2021-46703 in the wild and no public exploit code.

Affected packages and fixed versions:
- RazorEngine (NuGet): affected all versions up to 4.5.1-alpha001; no fix listed
- RazorEngine (NuGet): affected all versions up to 4.5.1-alpha001; 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-2021-46703/ (Markdown: https://insights.sbomify.com/CVE-2021-46703/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46703
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46703
- OSV: https://osv.dev/vulnerability/CVE-2021-46703

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46703/
Summaries are generated and may contain mistakes; the official description above is the record.