CVE-2024-51003 identifies multiple stack overflow vulnerabilities in the ap_mode.cgi component of several Netgear router models: R8500 v1.0.2.160, XR300 v1.0.3.78, R7000P v1.3.3.154, and R6400 v2 1.0.4.128. The vulnerabilities arise from improper handling of the apmode_dns1_pri and apmode_dns1_sec parameters, which are used to configure primary and secondary DNS settings in access point mode. By sending a specially crafted POST request containing malicious payloads in these parameters, an attacker with low privileges can trigger a stack overflow condition. This overflow leads to a denial of service (DoS) by crashing or destabilizing the router’s firmware, thereby interrupting network connectivity. The CVSS 3.1 base score is 5.7, reflecting medium severity, with an attack vector of adjacent network (AV:A), low attack complexity (AC:L), requiring privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), and impact limited to availability (A:H). There is no impact on confidentiality or integrity. The vulnerability is classified under CWE-120 (Classic Buffer Overflow). No patches or exploits are currently publicly available, but the flaw poses a risk to network availability for affected devices. The vulnerability underscores the importance of secure input validation in router firmware components handling network configuration parameters.

The primary impact of CVE-2024-51003 is denial of service, which can disrupt network availability for organizations using the affected Netgear routers. This can lead to temporary loss of internet connectivity, interruption of business operations, and potential downtime for critical services relying on these routers. Since the vulnerability requires low privileges but no user interaction, an attacker with network access—such as an insider or a compromised device within the local network or adjacent network segment—can exploit it. Although confidentiality and integrity are not affected, the availability impact can be significant for environments dependent on these routers for stable network infrastructure. This could affect small to medium businesses, home offices, and branch offices that use these consumer and prosumer-grade routers. The lack of known exploits reduces immediate risk, but the medium severity score indicates that exploitation could be leveraged in targeted attacks or combined with other vulnerabilities for greater impact.

Organizations should immediately identify if they are using any of the affected Netgear router models and firmware versions. Since no official patches are currently available, mitigation should focus on reducing exposure: restrict network access to the router’s management interfaces to trusted administrators only, preferably via VLAN segmentation or firewall rules limiting access to the router’s web interface. Disable remote management features if enabled. Monitor network traffic for unusual POST requests targeting ap_mode.cgi and specifically the apmode_dns1_pri and apmode_dns1_sec parameters. Implement network intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect and block exploit attempts. Plan for firmware updates from Netgear as soon as patches are released and apply them promptly. Additionally, consider replacing affected devices with models that have a stronger security track record if patching is delayed. Regularly audit router configurations and logs to detect anomalous activity indicative of exploitation attempts.