CVE-2024-42812 in DIR-860L
Summary
by MITRE • 08/19/2024
In D-Link DIR-860L v2.03, there is a buffer overflow vulnerability due to the lack of length verification for the SID field in gena.cgi. Attackers who successfully exploit this vulnerability can cause the remote target device to crash or execute arbitrary commands.
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Analysis
by VulDB Data Team • 06/15/2025
The vulnerability identified as CVE-2024-42812 affects the D-Link DIR-860L router model running firmware version v2.03, representing a critical buffer overflow flaw within the device's web interface management system. This vulnerability resides in the gena.cgi component which handles certain generic network announcements and is commonly used in upnp implementations for device discovery and notification services. The flaw specifically manifests when processing the SID field parameter without proper length validation, creating an exploitable condition that allows attackers to manipulate memory structures through crafted input sequences.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking permits data to overwrite adjacent memory locations. The gena.cgi script processes incoming requests from network devices that communicate using the upnp protocol, and the SID field serves as a session identifier for these communications. When an attacker sends a maliciously crafted request containing an oversized SID value, the device's processing routine fails to validate the input length against the allocated buffer space, resulting in memory corruption that can lead to system instability or complete device crash. This type of vulnerability falls under the ATT&CK technique T1210 - Exploitation of Remote Services, where adversaries leverage unpatched software vulnerabilities to gain unauthorized access or execute malicious code.
The operational impact of this vulnerability extends beyond simple device disruption, as successful exploitation can enable remote command execution capabilities that allow attackers to fully compromise the router's operational environment. This represents a severe threat to network security since the DIR-860L serves as a gateway device for home and small office networks, making it a prime target for attackers seeking persistent access to larger network infrastructures. The vulnerability affects the device's ability to maintain stable network operations, potentially creating denial of service conditions that disrupt legitimate network traffic while simultaneously providing attackers with a foothold for further network reconnaissance and lateral movement activities.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from D-Link to address the buffer overflow condition in gena.cgi, as recommended by the vendor's security advisory. Network administrators should implement network segmentation to limit exposure of affected devices to untrusted networks, while also monitoring for suspicious upnp traffic patterns that might indicate exploitation attempts. The implementation of web application firewalls and network access controls can help detect and prevent malformed requests targeting the vulnerable gena.cgi endpoint. Additionally, regular security assessments of network infrastructure should include vulnerability scanning for similar buffer overflow conditions in other network devices, as this type of flaw often indicates broader software quality issues that may affect other components of the router's firmware implementation. Organizations should also consider maintaining offline backups of device configurations and implementing robust network monitoring to detect unusual behavior that might indicate successful exploitation attempts.