CVE-2024-42815 in RE365
Summary
by MITRE • 08/19/2024
In the TP-Link RE365 V1_180213, there is a buffer overflow vulnerability due to the lack of length verification for the USER_AGENT field in /usr/bin/httpd. Attackers who successfully exploit this vulnerability can cause the remote target device to crash or execute arbitrary commands.
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Analysis
by VulDB Data Team • 08/22/2024
The vulnerability identified as CVE-2024-42815 affects the TP-Link RE365 wireless router model with firmware version V1_180213 and represents a critical buffer overflow flaw within the web server component of the device. This issue resides in the /usr/bin/httpd binary where the USER_AGENT field from HTTP requests is processed without proper length validation, creating an exploitable condition that can be leveraged by remote attackers to compromise the device's operational integrity. The vulnerability stems from inadequate input sanitization practices within the embedded web server implementation, specifically failing to enforce bounds checking on user-supplied data that flows into internal buffer structures. According to CWE-121, this represents a classic stack-based buffer overflow condition where attacker-controlled data exceeds the allocated buffer space, potentially leading to memory corruption and arbitrary code execution. The affected device operates with a web interface that handles HTTP traffic through the embedded httpd server, making it susceptible to remote exploitation when processing incoming requests that contain malicious USER_AGENT strings.
The technical exploitation of this vulnerability occurs when an attacker crafts a specially formatted HTTP request containing an overly long USER_AGENT header value that exceeds the predetermined buffer capacity within the httpd process. This condition results in memory overwrite behavior where the excess data overflows into adjacent memory locations, potentially corrupting program execution flow or allowing attackers to inject and execute malicious code within the router's memory space. The buffer overflow manifests through the lack of proper bounds checking mechanisms that should validate the length of incoming USER_AGENT data before copying it into internal storage buffers. This flaw directly aligns with ATT&CK technique T1210 which describes the exploitation of vulnerabilities in remote services to gain unauthorized access and execute arbitrary commands. The exploitation process typically involves sending a crafted HTTP request with an oversized USER_AGENT field to the router's web interface, which then processes this data through the vulnerable httpd binary, causing either a crash of the service or enabling remote code execution capabilities for the attacker.
The operational impact of CVE-2024-42815 extends beyond simple service disruption to encompass full device compromise and potential network infiltration. A successful exploitation allows attackers to execute arbitrary commands with the privileges of the httpd process, which typically runs with elevated permissions within the router's operating environment. This compromise can result in persistent backdoor access, data exfiltration, network traffic interception, or further lateral movement within the compromised network infrastructure. The vulnerability affects devices that are typically deployed in residential and small office environments where network security may be insufficiently implemented, making them attractive targets for attackers seeking to establish persistent access points within networks. The remote nature of the attack means that exploitation can occur from anywhere on the internet without requiring physical access to the device, significantly increasing the attack surface and potential impact. Organizations relying on TP-Link RE365 devices for network infrastructure should consider this vulnerability as a critical threat to their network security posture, particularly in environments where these devices are directly exposed to external network traffic.
Mitigation strategies for CVE-2024-42815 should prioritize immediate firmware updates from TP-Link to address the underlying buffer overflow condition through proper input validation and bounds checking mechanisms. Network administrators should implement network segmentation to isolate affected devices from critical network segments and deploy intrusion detection systems to monitor for suspicious HTTP traffic patterns that may indicate exploitation attempts. The implementation of web application firewalls and HTTP request filtering can help prevent overly long USER_AGENT headers from reaching the vulnerable httpd process. Additionally, disabling unnecessary services and ports, particularly those related to the web interface when not required for management purposes, can reduce the attack surface. Security monitoring should include regular vulnerability scanning of network infrastructure to identify other potentially affected devices running similar firmware versions. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly within network infrastructure devices where the consequences of exploitation can be severe. Organizations should also consider implementing network access controls and regular security audits to ensure that firmware updates are properly applied and that devices remain protected against similar vulnerabilities in the future.