CVE-2009-5157 in WAG54G2
Summary
by MITRE
On Linksys WAG54G2 1.00.10 devices, there is authenticated command injection via shell metacharacters in the setup.cgi c4_ping_ipaddr variable.
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Analysis
by VulDB Data Team • 10/03/2023
The vulnerability CVE-2009-5157 represents a critical command injection flaw in Linksys WAG54G2 wireless access points running firmware version 1.00.10. This issue affects network devices that process user input through web-based administrative interfaces, specifically targeting the setup.cgi script that handles network configuration parameters. The vulnerability exists within the device's web management interface where unvalidated user input is directly incorporated into system commands without proper sanitization or escaping mechanisms. This allows authenticated attackers who have access to the device's administrative interface to inject malicious shell commands through the c4_ping_ipaddr parameter, effectively bypassing normal input validation controls.
The technical exploitation of this vulnerability occurs when an authenticated user submits specially crafted input containing shell metacharacters through the c4_ping_ipaddr variable in the setup.cgi script. The device processes this input without proper sanitization, leading to arbitrary command execution within the device's operating system context. This command injection vulnerability maps to CWE-77 which specifically addresses improper neutralization of special elements used in commands, and CWE-94 which covers improper control of generation of code. The attack vector leverages the device's built-in ping functionality that is intended for network diagnostics but becomes a conduit for malicious command execution when input is not properly validated.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the ability to gain full administrative control over the affected wireless access point. An attacker could potentially execute system commands such as modifying network configurations, accessing stored credentials, installing malicious software, or even creating backdoors for persistent access. The vulnerability affects the device's core network functionality and could be exploited to disrupt network services or establish unauthorized network access points. This represents a significant risk to network security as wireless access points often serve as gateways to corporate or residential networks, making them prime targets for attackers seeking lateral movement within network environments.
Mitigation strategies for this vulnerability should include immediate firmware updates from Linksys to address the command injection flaw, along with network segmentation and access control measures. Organizations should implement strict administrative access controls, ensuring that only authorized personnel have access to device management interfaces. Network monitoring should be enhanced to detect unusual command execution patterns or unauthorized configuration changes. The vulnerability also highlights the importance of input validation and sanitization practices in web applications, aligning with ATT&CK technique T1059.001 for command and script injection. Additionally, implementing network access controls and disabling unnecessary services on the device can reduce the attack surface. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network equipment, as this vulnerability type commonly affects embedded systems and network appliances that lack robust input validation mechanisms.