# CVE-2024-23324: Envoy ext auth can be bypassed when Proxy protocol filter sets invalid UTF-8 metadata

> Attackers can bypass external authentication in Envoy proxy by sending invalid UTF-8 metadata when failure_mode_allow is enabled.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/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:** 9 Feb 2024
- **Updated:** 19 Aug 2024
- **Also known as:** BIT-envoy-2024-23324, GHSA-gq3v-vvhj-96j6

## What is CVE-2024-23324?

CVE-2024-23324 is a high-severity authentication bypass vulnerability in Envoyproxy Envoy, published on 9 Feb 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Envoy is a high-performance edge/middle/service proxy. External authentication can be bypassed by downstream connections. Downstream clients can force invalid gRPC requests to be sent to ext_authz, circumventing ext_authz checks when failure_mode_allow is set to true. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2024-23324?

1 open source package ship an affected version, including envoy. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `envoy` | Bitnami | From 1.26.0 | 1.26.7, 1.27.3, 1.28.1, 1.29.1 |

Products: Envoyproxy Envoy.

## How do I fix CVE-2024-23324?

Upgrade envoy to a fixed version for your release line: 1.26.7, 1.27.3, 1.28.1 or 1.29.1.

## Is CVE-2024-23324 being exploited?

There is no known exploitation of CVE-2024-23324 in the wild and no public exploit code.

## Other vulnerabilities in Envoyproxy Envoy

- [CVE-2022-29226](https://insights.sbomify.com/CVE-2022-29226/): Trivial authentication bypass in Envoy (critical 10.0)
- [CVE-2019-18801](https://insights.sbomify.com/CVE-2019-18801/): Memory corruption in n/a (critical 9.8)
- [CVE-2019-18802](https://insights.sbomify.com/CVE-2019-18802/): Security feature bypass in n/a (critical 9.8)
- [CVE-2020-35470](https://insights.sbomify.com/CVE-2020-35470/): Information disclosure in n/a (high 8.8)
- [CVE-2023-35941](https://insights.sbomify.com/CVE-2023-35941/): Envoy vulnerable to OAuth2 credentials exploit with permanent validity (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-23324 and fix it if it is affected.

What it is: CVE-2024-23324 is a high-severity authentication bypass vulnerability in Envoyproxy Envoy, published on 9 Feb 2024. 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-2024-23324 in the wild and no public exploit code.

Affected packages and fixed versions:
- envoy (Bitnami): affected from 1.26.0; fixed in 1.26.7, 1.27.3, 1.28.1, 1.29.1

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-2024-23324/ (Markdown: https://insights.sbomify.com/CVE-2024-23324/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-23324
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-23324
- OSV: https://osv.dev/vulnerability/CVE-2024-23324

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-23324/
Summaries are generated and may contain mistakes; the official description above is the record.