CVE-2020-6872 in R5300 G4
Summary
by MITRE
The server management software module of ZTE has a storage XSS vulnerability. The attacker inserts some attack codes through the foreground login page, which will cause the user to execute the predefined malicious script in the browser. This affects <R5300G4V03.08.0100/V03.07.0300/V03.07.0200/V03.07.0108/V03.07.0100/V03.05.0047/V03.05.0046/V03.05.0045/V03.05.0044/V03.05.0043/V03.05.0040/V03.04.0020;R8500G4V03.07.0103/V03.07.0101/V03.06.0100/V03.05.0400/V03.05.0020;R5500G4V03.08.0100/V03.07.0200/V03.07.0100/V03.06.0100>.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/21/2020
The vulnerability identified as CVE-2020-6872 represents a critical storage cross-site scripting flaw within the server management software module of ZTE devices. This security weakness manifests in the form of a persistent XSS vulnerability that allows attackers to inject malicious scripts into the system through the frontend login interface. The vulnerability specifically affects multiple ZTE router models including R5300G4, R8500G4, and R5500G4 series across various firmware versions, creating a widespread exposure across the vendor's product portfolio. The flaw occurs when user-supplied input is not properly sanitized or validated before being stored and subsequently rendered back to users, enabling attackers to execute arbitrary code within the victim's browser context.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding mechanisms within the web-based management interface. When legitimate users authenticate and interact with the system through the login page, any malicious payload injected by an attacker gets stored within the application's database or storage layer. This stored content is then retrieved and displayed to other users who access the affected system, causing their browsers to execute the embedded malicious scripts. The vulnerability is classified as a storage XSS (also known as persistent XSS) due to the persistence of the malicious code beyond a single user session. This classification aligns with CWE-79 which defines cross-site scripting vulnerabilities where untrusted data is directly output to users without proper sanitization, and specifically maps to CWE-79-242 which addresses storage-based XSS implementations.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a potent vector for various malicious activities within the compromised network environment. Once an attacker successfully injects malicious code, they can potentially steal user sessions, capture sensitive authentication credentials, perform unauthorized administrative actions, or redirect victims to phishing sites. The persistence nature of the vulnerability means that even after the initial injection, the malicious payload continues to affect all users who access the affected management interface, creating a sustained threat vector. The affected ZTE router models represent critical network infrastructure components that serve as gateways for enterprise and residential networks, making this vulnerability particularly dangerous from a network security perspective. The vulnerability's impact is further amplified by the fact that it affects multiple firmware versions across different product lines, suggesting a systemic issue in the software development lifecycle that requires comprehensive remediation.
Organizations affected by this vulnerability should implement immediate mitigations including network segmentation to limit access to the management interfaces, deployment of web application firewalls to detect and block malicious payloads, and implementation of strict input validation controls. The recommended approach involves applying vendor-provided security patches as soon as they become available, which typically address the root cause by implementing proper input sanitization and output encoding mechanisms. Additionally, network administrators should consider disabling unnecessary management interfaces, implementing multi-factor authentication, and conducting regular security assessments to identify potential injection points. This vulnerability aligns with several ATT&CK techniques including T1059.007 for command and scripting interpreter and T1566 for credential harvesting, making it a significant concern for organizations implementing security frameworks such as NIST Cybersecurity Framework or ISO 27001. The vulnerability demonstrates the importance of secure coding practices and proper input validation in network infrastructure software, particularly in management interfaces that handle user-supplied data. Given the widespread nature of affected firmware versions, organizations should also consider conducting comprehensive inventory assessments to identify all potentially vulnerable devices and implement coordinated patch management strategies to ensure complete remediation across their network infrastructure.