CVE-2005-2799 in WRT54G
Summary
by MITRE
Buffer overflow in apply.cgi in Linksys WRT54G 3.01.03, 3.03.6, and possibly other versions before 4.20.7, allows remote attackers to execute arbitrary code via a long HTTP POST request.
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Analysis
by VulDB Data Team • 10/24/2024
The vulnerability identified as CVE-2005-2799 represents a critical buffer overflow flaw in the apply.cgi component of Linksys WRT54G wireless routers. This issue affects specific firmware versions including 3.01.03, 3.03.6, and potentially other releases prior to 4.20.7, creating a significant security risk for network infrastructure devices. The flaw resides within the web management interface of these routers, which serves as the primary point of interaction for administrators to configure network settings and device parameters.
The technical implementation of this vulnerability stems from inadequate input validation within the apply.cgi script that processes HTTP POST requests. When a remote attacker sends a malformed HTTP POST request containing an excessively long payload, the application fails to properly bounds-check the input data before copying it into a fixed-size buffer. This classic buffer overflow condition occurs because the system does not verify that the incoming data length exceeds the allocated buffer capacity, allowing the attacker to overwrite adjacent memory locations with malicious code. The vulnerability specifically affects the router's web server component that handles configuration changes, making it accessible through the standard HTTP interface without requiring authentication.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with complete control over affected devices. Successful exploitation enables adversaries to gain root-level access to the router's operating system, potentially allowing them to modify network configurations, redirect traffic, install malware, or establish persistent backdoors. The attack vector requires only a remote HTTP POST request, making it particularly dangerous as it can be exploited from anywhere on the internet without physical access to the device. Network administrators may remain unaware of compromise until malicious activities have already occurred, as the exploitation does not necessarily generate obvious network traffic patterns or system alerts.
This vulnerability aligns with CWE-121, which describes buffer overflow conditions in stack-based buffers, and represents a common weakness in embedded systems and network devices where memory management is often simplified for resource-constrained environments. The ATT&CK framework categorizes this issue under T1059.007 for command and scripting interpreter, as exploitation typically involves executing arbitrary commands through the compromised device. The affected Linksys WRT54G series devices represent a significant portion of consumer and small office network infrastructure, making this vulnerability particularly widespread and concerning for network security professionals. Organizations should prioritize immediate firmware updates to version 4.20.7 or later, as this release contains the necessary patches to address the buffer overflow condition and prevent exploitation by remote attackers.
The broader implications of this vulnerability highlight the critical importance of secure coding practices in embedded network devices, particularly those handling network traffic and user input. Many embedded systems suffer from inadequate input validation and memory management controls due to resource constraints, creating security vulnerabilities that can be easily exploited by threat actors. This case demonstrates how seemingly minor implementation flaws in web server components can result in complete system compromise, emphasizing the need for comprehensive security testing and regular firmware updates in network infrastructure devices. The vulnerability also underscores the importance of network segmentation and monitoring to detect potential exploitation attempts, as the attack can occur without authentication and may not generate obvious network anomalies.