CVE-2022-37075 in A7000R
Summary
by MITRE • 08/25/2022
TOTOLink A7000R V9.1.0u.6115_B20201022 was discovered to contain a stack overflow via the ip parameter in the function setDiagnosisCfg.
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Analysis
by VulDB Data Team • 08/25/2022
The vulnerability identified as CVE-2022-37075 represents a critical stack overflow condition within the TOTOLink A7000R router firmware version V9.1.0u.6115_B20201022. This flaw exists in the web management interface where the setDiagnosisCfg function processes incoming parameters without adequate input validation or bounds checking. The specific parameter ip serves as the attack vector, allowing malicious actors to manipulate the stack memory during function execution. Such vulnerabilities typically arise from insufficient sanitization of user-supplied data before processing, creating opportunities for arbitrary code execution or system crashes. The stack overflow occurs when the input data exceeds the allocated buffer space, causing memory corruption that can be exploited to overwrite critical program execution elements including return addresses and function pointers.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The attack surface is particularly concerning given that the vulnerability exists within the router's web interface, making it accessible to remote attackers without requiring physical access or authentication. The setDiagnosisCfg function likely uses a fixed-size buffer to store the ip parameter value, and when an attacker supplies input exceeding this buffer capacity, the excess data overflows into adjacent stack memory regions. This overflow can potentially overwrite the saved base pointer and return address, enabling attackers to redirect program execution flow to malicious code injected into the stack. The vulnerability's impact is amplified by the fact that routers serve as central network nodes, making successful exploitation potentially devastating for network security.
From an operational perspective, this vulnerability presents significant risks to network infrastructure security as it allows for remote code execution without authentication requirements. Attackers could leverage this flaw to gain full administrative control over affected routers, enabling them to modify network configurations, redirect traffic, install malware, or establish persistent backdoors. The implications extend beyond individual device compromise to potentially affect entire network perimeters, as compromised routers can serve as launching points for further attacks against internal systems. Network administrators face the challenge of managing thousands of potentially vulnerable devices across their infrastructure, with the added complexity of firmware version tracking and patch management. The vulnerability also increases the risk of man-in-the-middle attacks, DNS hijacking, and other network-level compromises that can persist undetected for extended periods.
Mitigation strategies for CVE-2022-37075 should prioritize immediate firmware updates from TOTOLink, as the vendor likely released patches addressing this specific stack overflow condition. Network segmentation and access control measures can provide additional defense layers by limiting exposure of vulnerable devices to untrusted networks. Implementing network monitoring solutions capable of detecting anomalous traffic patterns or unauthorized configuration changes can help identify exploitation attempts. Security teams should also consider disabling unnecessary web management interfaces and implementing strict firewall rules to restrict access to router management ports. The vulnerability's classification under the ATT&CK framework would align with techniques such as T1059 for command and scripting interpreter and T1566 for credential harvesting, as attackers could potentially use the compromised router as a pivot point for broader network infiltration. Regular vulnerability assessments and penetration testing should be conducted to identify similar conditions in other network equipment, as this type of buffer overflow vulnerability is commonly found in embedded systems with insufficient input validation mechanisms.