CVE-2022-24155 in AX3
Summary
by MITRE • 02/04/2022
Tenda AX3 v16.03.12.10_CN was discovered to contain a heap overflow in the function setSchedWifi. This vulnerability allows attackers to cause a Denial of Service (DoS) via the schedStartTime and schedEndTime parameters.
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Analysis
by VulDB Data Team • 02/05/2022
The vulnerability identified as CVE-2022-24155 affects Tenda AX3 wireless router firmware version v16.03.12.10_CN and represents a critical heap overflow condition within the setSchedWifi function. This flaw exists in the router's web interface handling of scheduled wireless configuration parameters, specifically targeting the schedStartTime and schedEndTime input fields. The vulnerability stems from inadequate input validation and memory management practices within the firmware's scheduling functionality, creating a scenario where malicious input can overwrite adjacent heap memory regions. The heap overflow occurs when the device processes these time parameters without proper bounds checking or buffer size validation, allowing attackers to manipulate memory layout and potentially execute arbitrary code or cause system instability.
The technical exploitation of this vulnerability leverages the inherent weakness in how the firmware handles user-supplied data through the web administration interface. When an attacker submits carefully crafted values to the schedStartTime and schedEndTime parameters, the setSchedWifi function fails to validate the input length or format against allocated memory boundaries. This lack of proper input sanitization creates a condition where the heap memory allocated for storing time schedule data becomes corrupted, leading to unpredictable behavior and system crashes. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and demonstrates the classic pattern of insufficient bounds checking in memory management operations. The attack surface is particularly concerning as it requires no authentication, making it accessible through the web interface and potentially exploitable by remote attackers.
Operationally, this vulnerability presents a significant risk to network availability and system stability, as it enables remote attackers to induce Denial of Service conditions without requiring privileged access or authentication credentials. The DoS impact can manifest as complete service disruption, requiring manual reboot of the affected device to restore normal operation, or potentially more severe outcomes including persistent system instability that affects network connectivity for all devices connected to the router. The vulnerability's remote exploitability means that attackers can target multiple devices simultaneously across networks, amplifying the operational impact. This weakness directly violates the principle of least privilege and demonstrates inadequate security controls in the device's input validation mechanisms, creating potential for broader network disruption and service availability issues.
Mitigation strategies for CVE-2022-24155 should prioritize immediate firmware updates from Tenda to address the heap overflow condition and implement proper input validation controls. Network administrators should monitor for exploitation attempts and consider network segmentation to limit potential attack vectors. The implementation of web application firewalls and input filtering mechanisms can provide additional layers of protection, while regular firmware update procedures should be established to maintain device security posture. Security controls should align with the ATT&CK framework's defense evasion and privilege escalation tactics, ensuring that input validation and memory management practices prevent similar vulnerabilities from occurring in future deployments. Organizations should also consider implementing network monitoring solutions to detect anomalous behavior patterns associated with DoS attacks targeting network infrastructure devices.