CVE-2022-40851 in AC15
Summary
by MITRE • 09/23/2022
Tenda AC15 V15.03.05.19 contained a stack overflow via the function fromAddressNat.
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Analysis
by VulDB Data Team • 05/23/2025
The vulnerability identified as CVE-2022-40851 affects the Tenda AC15 wireless router model running firmware version V15.03.05.19 and represents a critical stack overflow condition within the network address translation functionality. This flaw manifests specifically within the fromAddressNat function, which processes network traffic routing operations. The stack overflow vulnerability occurs when the device receives specially crafted network packets that exceed the allocated buffer space within the fromAddressNat function implementation, potentially leading to arbitrary code execution or system crash conditions.
The technical exploitation of this vulnerability stems from insufficient input validation and buffer management within the router's firmware code. When network traffic passes through the NAT function, the device fails to properly validate the size and content of incoming packets before processing them through the fromAddressNat function. This allows attackers to craft malicious packets that deliberately exceed the predetermined buffer limits, causing the stack to overflow and potentially overwrite adjacent memory locations. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking permits memory corruption. The exploitation scenario typically involves sending malformed packets to the router's network interface, which then processes these packets through the vulnerable NAT function.
The operational impact of this vulnerability extends beyond simple device instability to encompass potential full system compromise and persistent access to network infrastructure. An attacker who successfully exploits this stack overflow could gain unauthorized access to the router's administrative interface, potentially enabling them to modify network configurations, redirect traffic, or establish persistent backdoors within the local network. This vulnerability directly maps to ATT&CK technique T1059.007 for command and control operations, as well as T1021.001 for remote services exploitation. The compromised device could serve as a pivot point for lateral movement within the network, allowing attackers to target other connected devices or escalate privileges to gain deeper system access. Additionally, the router's role as a network gateway makes it a prime target for attackers seeking to establish persistent access to critical network infrastructure.
Mitigation strategies for CVE-2022-40851 should prioritize immediate firmware updates from Tenda's official support channels, as the manufacturer has likely released patches addressing this specific stack overflow condition. Network administrators should implement additional protective measures including firewall rules that limit external access to router management interfaces, disable unnecessary services, and monitor network traffic for anomalous patterns that might indicate exploitation attempts. The implementation of network segmentation can help isolate vulnerable devices from critical network resources, while regular vulnerability scanning should identify other potentially affected devices within the network infrastructure. Security monitoring solutions should be configured to detect unusual traffic patterns or repeated connection attempts that could indicate exploitation activity. Organizations should also maintain detailed network documentation to quickly identify and respond to any unauthorized changes to router configurations that might result from successful exploitation of this vulnerability.