CVE-2011-0352 in WRT54GC
Summary
by MITRE
Buffer overflow in the web-based management interface on the Cisco Linksys WRT54GC router with firmware before 1.06.1 allows remote attackers to cause a denial of service (device crash) via a long string in a POST request.
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Analysis
by VulDB Data Team • 01/19/2025
The vulnerability identified as CVE-2011-0352 represents a critical buffer overflow flaw within the web-based management interface of Cisco Linksys WRT54GC wireless routers. This issue affects devices running firmware versions prior to 1.06.1 and demonstrates a classic security weakness that has persisted across numerous networking devices throughout the years. The vulnerability specifically manifests when the affected router processes POST requests containing excessively long strings, creating a condition where memory boundaries are exceeded and system stability is compromised.
The technical implementation of this buffer overflow occurs within the router's web management interface, which fails to properly validate input lengths before processing user-supplied data. When a remote attacker crafts a malicious POST request containing a string that exceeds the allocated buffer space, the overflow causes the router's memory management to behave unpredictably. This particular flaw resides in the HTTP server component that handles web interface communications, making it accessible over the network without requiring authentication or physical access to the device. The vulnerability operates at the application layer and affects the router's ability to process legitimate web requests while simultaneously allowing malicious input to corrupt memory structures.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it provides attackers with the capability to remotely crash the affected router and potentially disrupt network connectivity for all devices relying on that particular access point. The device crash results in complete service interruption, requiring manual intervention for recovery, which can be particularly problematic in enterprise environments or scenarios where network uptime is critical. Network administrators may experience significant disruption when multiple devices are simultaneously affected, and the vulnerability's remote exploitability means that attackers can target these devices from anywhere on the internet without requiring physical proximity or network access. This characteristic aligns with ATT&CK technique T1499.004 for network denial of service and represents a fundamental failure in input validation that violates security best practices outlined in CWE-121.
Mitigation strategies for CVE-2011-0352 primarily focus on firmware updates and network segmentation approaches to limit the attack surface. Cisco released firmware version 1.06.1 to address this vulnerability, and system administrators should prioritize immediate deployment of this update across all affected devices. Additionally, network administrators can implement firewall rules to restrict access to the router's web management interface from untrusted networks, though this approach provides only partial protection since the vulnerability exists within the device itself. The implementation of input validation controls and proper buffer management practices should be enforced at the application level, aligning with security standards that recommend against using vulnerable functions such as strcpy and strcat in favor of safer alternatives. Organizations should also consider implementing network monitoring to detect anomalous traffic patterns that might indicate exploitation attempts, and establish regular vulnerability assessment procedures to identify similar issues in other network infrastructure components. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date firmware and implementing robust input validation controls in embedded systems and network devices.