# CVE-2021-20150: Auth bypass in Trendnet AC2600 TEW-827DRU

> Attackers can bypass authentication and view admin information by forcing a redirect from the setup wizard on Trendnet routers.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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:** 30 Dec 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-6wmh-r824-376w

## What is CVE-2021-20150?

CVE-2021-20150 is a medium-severity authentication bypass vulnerability in Trendnet AC2600 TEW-827DRU, published on 30 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Trendnet AC2600 TEW-827DRU version 2.08B01 improperly discloses information via redirection from the setup wizard. Authentication can be bypassed and a user may view information as Admin by manually browsing to the setup wizard and forcing it to redirect to the desired page.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2021-20150?

It affects 1 product.


Products: Trendnet Tew-827dru Firmware.

## How do I fix CVE-2021-20150?

No fix has been published for CVE-2021-20150 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20150 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-20150 exists.

Public exploit code:

- Trendnet AC2600 TEW-827DRU - Credentials Disclosure (nuclei): http/cves/2021/CVE-2021-20150.yaml

## Other vulnerabilities in Trendnet AC2600 TEW-827DRU

- [CVE-2024-28354](https://insights.sbomify.com/CVE-2024-28354/): Command injection in n/a (critical 10.0)
- [CVE-2021-20151](https://insights.sbomify.com/CVE-2021-20151/): Auth bypass in Trendnet AC2600 TEW-827DRU (critical 10.0)
- [CVE-2021-20149](https://insights.sbomify.com/CVE-2021-20149/): Missing authorization in Trendnet AC2600 TEW-827DRU (critical 9.8)
- [CVE-2021-20155](https://insights.sbomify.com/CVE-2021-20155/): Hardcoded credentials in Trendnet AC2600 TEW-827DRU (critical 9.8)
- [CVE-2021-20158](https://insights.sbomify.com/CVE-2021-20158/): Auth bypass in Trendnet AC2600 TEW-827DRU (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20150 and fix it if it is affected.

What it is: CVE-2021-20150 is a medium-severity authentication bypass vulnerability in Trendnet AC2600 TEW-827DRU, published on 30 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-20150 exists.

Affected product: Trendnet AC2600 TEW-827DRU. 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-2021-20150/ (Markdown: https://insights.sbomify.com/CVE-2021-20150/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20150
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20150
- OSV: https://osv.dev/vulnerability/CVE-2021-20150

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20150/
Summaries are generated and may contain mistakes; the official description above is the record.