# CVE-2023-50463: Header spoofing in caddy-geo-ip

> Attackers can spoof source IP addresses via X-Forwarded-For headers to bypass IP-based access controls in Caddy's GeoIP middleware.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 10 Dec 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-rxg9-hgq7-8pwx, GO-2023-2394

## What is CVE-2023-50463?

CVE-2023-50463 is a medium-severity vulnerability in n/a, published on 10 Dec 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The caddy-geo-ip (aka GeoIP) middleware through 0.6.0 for Caddy 2, when trust_header X-Forwarded-For is used, allows attackers to spoof their source IP address via an X-Forwarded-For header, which may bypass a protection mechanism (trusted_proxy directive in reverse_proxy or IP address range restrictions).

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2023-50463?

3 open source packages ship an affected version, including github.com/shift72/caddy-geo-ip. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/shift72/caddy-geo-ip` | Go | All versions | None |
| `github.com/shift72/caddy-geo-ip` | Go | All versions to 0.6.0 | None |
| `github.com/shift72/caddy-geo-ip` | Go | All versions to 0.6.0 | None |

Products: Caddyserver Caddy.

## How do I fix CVE-2023-50463?

No fix has been published for CVE-2023-50463 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-50463 being exploited?

There is no known exploitation of CVE-2023-50463 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-21246](https://insights.sbomify.com/CVE-2018-21246/): Caddy vulnerable to Authentication Bypass due to mishandling of TLS client authentication (critical 9.8)
- [CVE-2026-27590](https://insights.sbomify.com/CVE-2026-27590/): Caddy: Unicode case-folding length expansion causes incorrect split_path index in FastCGI transport (high 8.9)
- [CVE-2026-27586](https://insights.sbomify.com/CVE-2026-27586/): Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed (high 8.8)
- [CVE-2026-45135](https://insights.sbomify.com/CVE-2026-45135/): Caddy: Unsafe Unicode Handling in FastCGI splitPos Allows Execution of Non-PHP Files (high 8.1)
- [CVE-2026-52845](https://insights.sbomify.com/CVE-2026-52845/): Caddy: FastCGI header normalization bypass in `forward_auth copy_headers` (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-50463 and fix it if it is affected.

What it is: CVE-2023-50463 is a medium-severity vulnerability in n/a, published on 10 Dec 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-50463 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/shift72/caddy-geo-ip (Go): affected all versions; no fix listed
- github.com/shift72/caddy-geo-ip (Go): affected all versions up to 0.6.0; no fix listed
- github.com/shift72/caddy-geo-ip (Go): affected all versions up to 0.6.0; 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-2023-50463/ (Markdown: https://insights.sbomify.com/CVE-2023-50463/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-50463
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-50463
- OSV: https://osv.dev/vulnerability/CVE-2023-50463

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-50463/
Summaries are generated and may contain mistakes; the official description above is the record.