CVE-2022-38313 in AC18
Summary
by MITRE • 09/07/2022
Tenda AC18 router v15.03.05.19 and v15.03.05.05 was discovered to contain a stack overflow via the time parameter at /goform/saveParentControlInfo.
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Analysis
by VulDB Data Team • 10/14/2022
The vulnerability identified as CVE-2022-38313 affects Tenda AC18 wireless routers running firmware versions v15.03.05.19 and v15.03.05.05. This represents a critical stack overflow flaw that exists within the router's web interface handling mechanism, specifically in the saveParentControlInfo form processing endpoint. The vulnerability manifests when the time parameter is manipulated during the parent control configuration process, creating a condition where user-supplied input is not properly validated or sanitized before being processed by the router's embedded web server.
The technical exploitation of this vulnerability occurs through a classic stack buffer overflow attack vector where malicious input data exceeds the allocated buffer space for the time parameter in the saveParentControlInfo form. This flaw falls under the Common Weakness Enumeration category of CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability is particularly concerning because it exists within the administrative interface of a network device that is typically accessible from within the local network, making it potentially exploitable by attackers who have gained access to the local network through other means.
From an operational perspective, this vulnerability presents significant risk to network security as it could allow remote code execution or system compromise when exploited by attackers with access to the local network. The impact extends beyond simple denial of service, as successful exploitation could enable attackers to gain unauthorized access to the router's administrative functions, potentially leading to complete network compromise. The vulnerability demonstrates poor input validation practices in the router's firmware implementation, where the time parameter field lacks proper bounds checking and sanitization mechanisms that would normally be expected in secure software development practices.
The attack surface for this vulnerability is relatively narrow but significant, as it requires an attacker to already have network access to the affected router's local network segment. However, the potential for privilege escalation and persistent access makes this a serious concern for network administrators. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: Unix Shell and T1021.001 for Remote Services: Remote Desktop Protocol, as exploitation could enable persistent access and command execution on the compromised device. Network defenders should consider this vulnerability as part of their broader assessment of IoT device security, particularly in environments where wireless routers are not properly segmented or monitored for anomalous network behavior.
Mitigation strategies for CVE-2022-38313 should include immediate firmware updates from Tenda to address the stack overflow condition, along with network segmentation to limit access to administrative interfaces. Network administrators should also implement proper monitoring of router administrative access patterns and consider disabling unnecessary administrative services when not actively required. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly those handling user-supplied data in network device firmware implementations. Additionally, organizations should conduct regular vulnerability assessments of their network infrastructure to identify similar issues in other network devices that may be running outdated firmware versions.