# CVE-2021-27250: Path traversal in DAP-2020

> Network-adjacent attackers can exploit a path traversal flaw in CGI scripts to disclose stored credentials on D-Link access points.

- **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:** 14 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-wr5r-74rp-qh45

## What is CVE-2021-27250?

CVE-2021-27250 is a medium-severity path traversal vulnerability in D-Link DAP-2020, published on 14 Apr 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 DAP-2020 v1.01rc001 Wi-Fi access points. Authentication is not required to exploit this vulnerability. The specific flaw exists within the processing of CGI scripts. When parsing the errorpage request parameter, the process does not properly validate a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to disclose stored credentials, leading to further compromise. Was ZDI-CAN-11856.

Weakness: CWE-73 (External Control of File Name or Path)

## Which versions are affected by CVE-2021-27250?

It affects 1 product.


Products: Dlink Dap-2020 Firmware.

## How do I fix CVE-2021-27250?

No fix has been published for CVE-2021-27250 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27250 being exploited?

There is no known exploitation of CVE-2021-27250 in the wild and no public exploit code.

## Other vulnerabilities in D-Link DAP-2020

- [CVE-2021-34861](https://insights.sbomify.com/CVE-2021-34861/): Memory corruption in DAP-2020 (high 8.8)
- [CVE-2021-34862](https://insights.sbomify.com/CVE-2021-34862/): Memory corruption in DAP-2020 (high 8.8)
- [CVE-2021-34863](https://insights.sbomify.com/CVE-2021-34863/): Memory corruption in DAP-2020 (high 8.8)
- [CVE-2021-27248](https://insights.sbomify.com/CVE-2021-27248/): Memory corruption in DAP-2020 (high 8.8)
- [CVE-2021-27249](https://insights.sbomify.com/CVE-2021-27249/): Command injection in DAP-2020 (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27250 and fix it if it is affected.

What it is: CVE-2021-27250 is a medium-severity path traversal vulnerability in D-Link DAP-2020, published on 14 Apr 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-2021-27250 in the wild and no public exploit code.

Affected product: D-Link DAP-2020. 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-2021-27250/ (Markdown: https://insights.sbomify.com/CVE-2021-27250/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27250
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27250
- OSV: https://osv.dev/vulnerability/CVE-2021-27250

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27250/
Summaries are generated and may contain mistakes; the official description above is the record.