CVE-2022-23919 in LinkHub Mesh Wifi MS1G
Summary
by MITRE • 08/06/2022
A stack-based buffer overflow vulnerability exists in the confsrv set_mf_rule functionality of TCL LinkHub Mesh Wifi MS1G_00_01.00_14. A specially-crafted network packet can lead to stack-based buffer overflow. An attacker can send a malicious packet to trigger this vulnerability.This vulnerability leverages the name field within the protobuf message to cause a buffer overflow.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/31/2022
The CVE-2022-23919 vulnerability represents a critical stack-based buffer overflow within the confsrv component of TCL LinkHub Mesh Wifi MS1G_00_01 firmware version 14. This vulnerability specifically manifests within the set_mf_rule functionality, which processes network packets containing protobuf messages. The flaw arises from insufficient input validation and bounds checking when handling the name field within these protobuf structures. The vulnerability classifies under CWE-121 Stack-based Buffer Overflow, a well-documented weakness that occurs when data is copied to a stack buffer without proper size validation, allowing adjacent memory to be overwritten. The attack vector requires an unauthenticated network connection to the affected device, making it particularly dangerous as it can be exploited from remote locations without requiring physical access or prior authentication. The protobuf message structure used by this firmware implementation does not enforce strict boundaries on the name field length, creating an opportunity for attackers to craft malicious packets that exceed the allocated stack buffer space.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as stack-based buffer overflows can potentially lead to arbitrary code execution or system compromise. When an attacker sends a specially-crafted network packet containing an excessively long name field within the protobuf message, the buffer overflow can overwrite adjacent stack memory locations including return addresses, function pointers, and local variables. This memory corruption can result in unpredictable behavior ranging from application crashes to complete system exploitation. The vulnerability affects the broader ecosystem of mesh WiFi networks, as the TCL LinkHub devices serve as critical infrastructure components that manage network policies and configurations. The exploitation of this vulnerability aligns with ATT&CK technique T1210 Exploitation of Remote Services, where adversaries leverage network-based vulnerabilities to gain unauthorized access to networked systems. Given that this vulnerability exists in network management functionality, it represents a significant risk to network security posture, particularly in enterprise environments where such devices are used to manage large-scale wireless networks.
Mitigation strategies for CVE-2022-23919 should prioritize immediate firmware updates from TCL to address the root cause of the buffer overflow. Organizations should implement network segmentation and access controls to limit exposure of affected devices to untrusted networks, utilizing firewalls and access control lists to restrict communication with the vulnerable confsrv component. Network monitoring solutions should be configured to detect anomalous protobuf message patterns and unusually long name fields that may indicate exploitation attempts. The implementation of input validation controls at network boundaries can help prevent malformed packets from reaching the vulnerable device, though this represents a secondary defense measure. Security teams should also consider disabling unused network services and ports on affected devices to minimize attack surface. Additionally, implementing intrusion detection systems with signatures specifically targeting this vulnerability can provide early warning of exploitation attempts. The vulnerability highlights the importance of secure coding practices, particularly around buffer management and input validation, and serves as a reminder of the need for comprehensive security testing of network infrastructure components. Organizations should also conduct thorough inventory assessments to identify all instances of affected TCL LinkHub devices and prioritize remediation efforts based on risk exposure and network criticality.