CVE-2024-36650 in A3100R
Summary
by MITRE • 06/11/2024
TOTOLINK AC1200 Wireless Dual Band Gigabit Router firmware A3100R V4.1.2cu.5247_B20211129, in the cgi function `setNoticeCfg` of the file `/lib/cste_modules/system.so`, the length of the user input string `NoticeUrl` is not checked. This can lead to a buffer overflow, allowing attackers to construct malicious HTTP or MQTT requests to cause a denial-of-service attack.
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Analysis
by VulDB Data Team • 06/14/2024
The vulnerability identified as CVE-2024-36650 affects TOTOLINK AC1200 Wireless Dual Band Gigabit Router firmware version A3100R V4.1.2cu.5247_B20211129 and represents a critical buffer overflow flaw within the system.so module. This vulnerability exists in the cgi function setNoticeCfg which processes user input through the NoticeUrl parameter without proper length validation. The absence of input sanitization creates a dangerous condition where malicious actors can exploit this weakness to overwrite adjacent memory locations in the router's firmware execution environment.
The technical implementation of this vulnerability resides in the /lib/cste_modules/system.so file where the setNoticeCfg function fails to validate the length of the NoticeUrl parameter before processing it. When an attacker submits a specially crafted URL exceeding the allocated buffer space, the excess data overflows into adjacent memory segments, potentially corrupting critical program state information or executing arbitrary code. This type of vulnerability maps directly to CWE-121, which describes stack-based buffer overflow conditions, and also aligns with CWE-787, describing out-of-bounds write conditions. The operational impact extends beyond simple memory corruption as the attacker can manipulate the router's behavior through crafted HTTP or MQTT requests that leverage this buffer overflow to cause system instability.
The potential for denial-of-service attacks through this vulnerability creates significant operational risks for network administrators and end users. An attacker who successfully exploits this buffer overflow can cause the router to crash, reboot continuously, or become unresponsive to legitimate network traffic. This disruption affects network availability and can potentially create security gaps in network infrastructure. The vulnerability is particularly concerning because it exists in a core system module that handles notification configuration, making it accessible through standard web interface interactions. Network security frameworks like MITRE ATT&CK categorize this type of vulnerability under T1499.004, which covers network denial of service, and T1566.002, involving spearphishing via web applications, as attackers can craft malicious URLs to exploit this weakness.
Mitigation strategies for CVE-2024-36650 should prioritize immediate firmware updates from TOTOLINK to address the root cause of the buffer overflow. Network administrators should implement network segmentation to limit access to router management interfaces and deploy intrusion detection systems to monitor for suspicious HTTP or MQTT traffic patterns. Additionally, access controls should be strengthened through the implementation of multi-factor authentication and restricted administrative access windows. The vulnerability highlights the importance of input validation in embedded systems and demonstrates how seemingly simple parameter handling can create critical security weaknesses. Organizations should also consider implementing network monitoring solutions that can detect unusual traffic patterns indicating potential exploitation attempts, while maintaining regular security assessments of network infrastructure to identify similar vulnerabilities in other firmware components.