External risk intelligence

D-Link Router Remote Command Execution Vulnerability.

CVE advisoryKnown Exploit

CVE-2021-45382

A vulnerability in certain D-Link routers' DDNS function allows for remote command execution. This exposes organizations to risks of unauthorized device control and potential data breaches. Affected router models are past their end-of-life and will not be patched, increasing business risk.

5Halo Surface Signal

OS Command Injection

Dlink Dir 820l Firmware

External exposure likelihood

Halo Surface Signal score for CVE-2021-45382

The affected products are consumer and small office routers, which are internet-edge devices by design. Their role involves managing network traffic and providing connectivity, inherently placing them at the network perimeter.

Horizon Alert

Summary of the vulnerability and why it matters

Certain D-Link router models are vulnerable due to a flaw in their DDNS function. This weakness allows for remote command execution, meaning an unauthorized party could potentially run commands on the affected devices. The main business impact could involve unauthorized access to or control over network devices, potentially disrupting operations or leading to data breaches.

  • Router DDNS function
  • Remote command execution flaw
  • Network device compromise

Attack Path

How an attacker could exploit the issue

A vulnerability in the DDNS function of certain D-Link routers allows for remote command execution. This occurs through the `ncc2` binary file, enabling an attacker to gain control over the affected device. Organizations using these routers face a significant risk to their network infrastructure and data integrity.

  • Exposure via network access.
  • Attacker sends malicious commands.
  • Control of device and network.

Live Threat

Current exploitation, exposure, and threat context

A critical vulnerability affects certain D-Link router models, allowing remote command execution. This means an attacker could potentially gain control of the affected devices without any user interaction. The vendor has indicated these products are past their end-of-life and will not receive patches.

  • Attackers with low skill levels could exploit this.
  • No special access or conditions are needed.
  • Business risk is high due to unpatched, internet-facing devices.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

An organization faces a critical risk due to a remote command execution vulnerability in specific D-Link router models. This vulnerability can be exploited through the DDNS function, potentially allowing unauthorized access and control. Given that these router models have reached their End of Life, the vendor will not provide patches, necessitating a proactive approach to mitigate the risk.

  • Identify all affected router assets on the network.
  • Isolate or disable exposed routers.
  • Replace EOL devices and monitor network activity.

Frequently asked questions

What D-Link routers are affected by CVE-2021-45382 and what is their function?

CVE-2021-45382 affects D-Link router models DIR-810L, DIR-820L/LW, DIR-826L, DIR-830L, and DIR-836L, across all hardware revisions. These devices are used to provide network connectivity and manage internet access for homes and small offices.

What type of weakness does CVE-2021-45382 represent and how is it triggered?

This vulnerability is classified as a 'Command Injection' (CWE-78) weakness. It means an attacker can inject operating system commands through the router's DDNS function, potentially taking control of the device.

How can an attacker exploit this D-Link router vulnerability?

An attacker can exploit this vulnerability by sending specially crafted commands through the router's DDNS function, specifically via the `ncc2` binary file. This allows for remote command execution without needing special access or conditions.

What is the relevance of CVE-2021-45382 given its impact and vendor response?

The affected D-Link routers are internet-edge devices, making them prime targets. The vendor has declared these models End of Life (EOL) and will not provide patches, meaning the vulnerability remains unaddressed on these devices.

What practical steps should an organization take to respond to this D-Link router vulnerability?

Organizations should identify all affected D-Link router assets, isolate or disable any exposed EOL devices, and replace them with updated hardware. Continuous network activity monitoring is also advised to detect any potential compromise.

References