CVE-2022-41517 in NR1800X
Summary
by MITRE • 10/06/2022
TOTOLINK NR1800X V9.1.0u.6279_B20210910 was discovered to contain a stack overflow in the lang parameter in the setLanguageCfg function
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Analysis
by VulDB Data Team • 10/30/2022
The vulnerability identified as CVE-2022-41517 affects the TOTOLINK NR1800X router firmware version V9.1.0u.6279_B20210910, representing a critical stack overflow condition that resides within the setLanguageCfg function. This flaw manifests when processing the lang parameter, indicating a classic buffer management issue where insufficient bounds checking allows malicious input to overwrite adjacent memory regions. The vulnerability stems from improper input validation mechanisms that fail to enforce size limitations on user-supplied data, creating an exploitable condition that can be leveraged by remote attackers to disrupt normal system operations or execute arbitrary code.
The technical implementation of this vulnerability places the device at significant risk due to the nature of stack-based buffer overflows which can lead to complete system compromise. When an attacker crafts a malicious payload containing an oversized lang parameter, the firmware's handling routine fails to properly validate the input length, causing the stack memory to overflow and potentially overwrite return addresses, function pointers, or other critical program state information. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a high-severity issue in the Common Weakness Enumeration catalog. The attack surface extends to any remote entity capable of sending HTTP requests to the affected device, making it particularly dangerous in networked environments where unauthorized access can occur through web-based management interfaces.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential full system compromise and persistent access. An attacker exploiting this condition could gain unauthorized control over the router's operating system, enabling them to modify network configurations, intercept traffic, establish backdoors, or use the device as a pivot point for attacking other systems within the local network. The specific function setLanguageCfg suggests this vulnerability affects language configuration settings which are typically accessible through web interfaces, making exploitation relatively straightforward for attackers familiar with the device's management protocols. According to ATT&CK framework, this vulnerability maps to T1059.007 Command and Scripting Interpreter: PowerShell and T1021.001 Remote Services: Remote Desktop Protocol, as attackers could potentially leverage the compromised device for lateral movement and command execution within networked environments.
Mitigation strategies for CVE-2022-41517 should prioritize immediate firmware updates from TOTOLINK, as the vendor has likely released patches addressing this specific stack overflow condition. Network administrators should implement robust access controls limiting administrative access to the device to trusted IP addresses only, while also deploying intrusion detection systems capable of identifying suspicious HTTP requests containing oversized parameters. Additionally, implementing network segmentation and monitoring for unusual traffic patterns can help detect exploitation attempts. Security teams should also consider disabling unnecessary web management interfaces when not actively required, as this reduces the attack surface. The vulnerability highlights the critical importance of input validation and proper memory management in embedded systems, emphasizing that devices handling user-supplied data must implement comprehensive bounds checking and sanitization routines to prevent similar conditions from occurring in future deployments.