External risk intelligence

Dlink DIR-816A2 Remote Code Execution via SSID Parameter

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2024-24321

The affected product is a consumer wireless router. Routers are designed to be deployed as internet edge devices, making their management interfaces and configuration functions, such as the one containing this vulnerability, reachable from the network.

Dlink Dir 816 Firmware

1.10cnb05

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory concerns a critical vulnerability in Dlink DIR-816A2 firmware, version 1.10CNB05. The issue could allow remote attackers to execute arbitrary code, potentially impacting network security and stability. The main concern at this time is to confirm if this technology is relevant to our environment and if it is exposed.

Allows remote code execution.
Important for network edge device security.
Confirm relevance and exposure.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by sending a specially crafted request over the network to the affected device. This request targets the `wizardstep4_ssid_2` parameter within the `sub_42DA54` function. Successful exploitation could allow an attacker to execute arbitrary code on the device.

Reachable via the network.
Triggered by a crafted parameter.
Allows arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an unauthenticated remote attacker to execute arbitrary code on affected devices by sending a specially crafted request. This could impact the device's intended function and potentially allow for unauthorized control over its network traffic.

Router system access.
Remote code execution via parameter.
Unauthorized control of network traffic.

Operational Fix

Recommended remediation, mitigation, and detection steps

System owners and potentially network or security teams are likely responsible for addressing this vulnerability, given it affects a network-edge device. The first practical step is to identify all instances of the affected router, confirm its internet exposure and business criticality, and then assign ownership for remediation planning.

Own by asset owner or network team.
Verify internet exposure and business criticality.
Plan phased rollout or vendor engagement.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is the Dlink DIR-816A2?

The Dlink DIR-816A2 is a consumer-grade wireless router. These devices act as the gateway between a local home or small office network and the internet, managing traffic routing and wireless connectivity for connected devices.

What does CWE-77 mean for CVE-2024-24321?

CVE-2024-24321 is classified as CWE-77, or Improper Neutralization of Special Elements used in a Command. In simple terms, the router fails to properly filter user input. An attacker can hide malicious system commands inside a legitimate data field, which the router then mistakenly executes as if it were a system instruction.

How is this vulnerability triggered?

An attacker triggers this by sending a specifically formatted request to the router containing malicious code in the wizardstep4_ssid_2 parameter. Simply browsing the web or using the router for standard traffic does not trigger the flaw; it requires a targeted, crafted interaction specifically aimed at this configuration function.

Why is this router considered high risk?

Halo Surface Signal notes that routers are inherently internet-facing edge devices. Because this specific flaw exists in a configuration function, it is reachable from the network, meaning an attacker does not need physical access to the device to attempt to take control of it.

How should I respond to this advisory?

First, inventory your network to locate any instances of the DIR-816A2 running firmware version 1.10CNB05. Once identified, confirm if the devices are exposed to the internet and assess their business importance to prioritize them for decommissioning or replacement, as they serve as a critical entry point to your network.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.