# CVE-2020-29238: Integer overflow in n/a

> Remote attackers can obtain sensitive information from ExpressVPN Routers acting as reverse proxies via crafted requests exploiting an integer overflow.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:** No
- **Published:** 10 Mar 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-647h-v8f6-577g

## What is CVE-2020-29238?

CVE-2020-29238 is a high-severity vulnerability in n/a, published on 10 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An integer buffer overflow in the Nginx webserver of ExpressVPN Router version 1 allows remote attackers to obtain sensitive information when the server running as reverse proxy via specially crafted request.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2020-29238?

It affects 1 product.


Products: Expressvpn Expressvpn.

## How do I fix CVE-2020-29238?

No fix has been published for CVE-2020-29238 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-29238 being exploited?

There is no known exploitation of CVE-2020-29238 in the wild and no public exploit code.

Public exploit code:

- ExpressVPN VPN Router 1.0 - Router Login Panel's Integer Overflow (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2024-25728](https://insights.sbomify.com/CVE-2024-25728/): Information disclosure in n/a (high 7.5)
- [CVE-2018-15490](https://insights.sbomify.com/CVE-2018-15490/): Path traversal in n/a (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-29238 and fix it if it is affected.

What it is: CVE-2020-29238 is a high-severity vulnerability in n/a, published on 10 Mar 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-2020-29238 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2020-29238/ (Markdown: https://insights.sbomify.com/CVE-2020-29238/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29238
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29238
- OSV: https://osv.dev/vulnerability/CVE-2020-29238

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-29238/
Summaries are generated and may contain mistakes; the official description above is the record.