# CVE-2020-27863: Auth bypass in Multiple Routers

> Network-adjacent attackers can bypass authentication on D-Link routers to disclose stored credentials via flawed string matching in the dhttpd service.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Feb 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-wpfj-wc8p-wv72

## What is CVE-2020-27863?

CVE-2020-27863 is a medium-severity authentication bypass vulnerability in D-Link Multiple Routers, published on 11 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

This vulnerability allows network-adjacent attackers to disclose sensitive information on affected installations of D-Link DVA-2800 and DSL-2888A routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the dhttpd service, which listens on TCP port 8008 by default. The issue results from incorrect string matching logic when accessing protected pages. An attacker can leverage this vulnerability to disclose stored credentials, leading to further compromise. Was ZDI-CAN-10912.

Weakness: CWE-287 (Improper Authentication), CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2020-27863?

It affects 2 products.


Products: Dlink Dsl-2888a Firmware, Dlink Dva-2800 Firmware.

## How do I fix CVE-2020-27863?

No fix has been published for CVE-2020-27863 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27863 being exploited?

There is no known exploitation of CVE-2020-27863 in the wild and no public exploit code.

## Other vulnerabilities in D-Link Multiple Routers

- [CVE-2021-33346](https://insights.sbomify.com/CVE-2021-33346/): Missing authorization in n/a (critical 9.8)
- [CVE-2020-27862](https://insights.sbomify.com/CVE-2020-27862/): Command injection in Multiple Routers (high 8.8)
- [CVE-2020-24577](https://insights.sbomify.com/CVE-2020-24577/): Information disclosure in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27863 and fix it if it is affected.

What it is: CVE-2020-27863 is a medium-severity authentication bypass vulnerability in D-Link Multiple Routers, published on 11 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-27863 in the wild and no public exploit code.

Affected product: D-Link Multiple Routers. 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-2020-27863/ (Markdown: https://insights.sbomify.com/CVE-2020-27863/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27863
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27863
- OSV: https://osv.dev/vulnerability/CVE-2020-27863

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27863/
Summaries are generated and may contain mistakes; the official description above is the record.