CVE-2024-2490 in AC18
Summary
by MITRE • 03/15/2024
A vulnerability classified as critical was found in Tenda AC18 15.03.05.05. Affected by this vulnerability is the function setSchedWifi of the file /goform/openSchedWifi. The manipulation of the argument schedStartTime/schedEndTime leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-256897 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 01/14/2025
This critical vulnerability exists in the Tenda AC18 wireless router firmware version 15.03.05.05 and specifically affects the setSchedWifi function within the /goform/openSchedWifi file. The flaw represents a stack-based buffer overflow that occurs when manipulating the schedStartTime and schedEndTime arguments, creating a significant security risk for affected devices. The vulnerability's classification as critical indicates the potential for severe impact including complete system compromise and unauthorized access to network resources.
The technical implementation of this vulnerability stems from improper input validation within the web form handling mechanism of the router's firmware. When users submit scheduling parameters through the web interface, the system fails to properly bounds-check the input data before copying it into fixed-size stack buffers. This allows an attacker to overflow the buffer and potentially overwrite adjacent memory locations, including return addresses and control data. The vulnerability is particularly dangerous because it can be exploited remotely without requiring physical access to the device, making it a prime target for automated attacks in wide-scale campaigns.
The operational impact of this vulnerability extends beyond simple denial of service or data corruption. Attackers who successfully exploit this buffer overflow can achieve arbitrary code execution on the affected router, potentially gaining full administrative control over the device. This compromise enables malicious actors to modify network configurations, redirect traffic through malicious proxies, install persistent backdoors, or use the device as a launching point for attacks against other systems within the network. The fact that the exploit has been publicly disclosed and is actively being used increases the risk to organizations and individuals who have not yet patched their affected devices.
Security professionals should immediately implement mitigation strategies including firmware updates from Tenda if available, network segmentation to isolate affected devices, and monitoring for suspicious network activity. The vulnerability aligns with CWE-121 stack-based buffer overflow and demonstrates characteristics consistent with attack patterns documented in the MITRE ATT&CK framework under techniques involving privilege escalation and persistent threats. Organizations should also consider implementing intrusion detection systems to monitor for exploitation attempts and maintain comprehensive network monitoring to detect unauthorized access or configuration changes that might indicate successful exploitation of this vulnerability. Given the vendor's lack of response to early disclosure, users may need to rely on community-driven patches or consider replacing affected devices with newer models that have proper input validation mechanisms in place.