CVE-2020-15499 in RT-AC1900P
Summary
by MITRE
An issue was discovered on ASUS RT-AC1900P routers before 3.0.0.4.385_20253. They allow XSS via spoofed Release Notes on the Firmware Upgrade page.
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Analysis
by VulDB Data Team • 08/26/2020
The vulnerability identified as CVE-2020-15499 affects ASUS RT-AC1900P routers running firmware versions prior to 3.0.0.4.385_20253, representing a critical cross-site scripting flaw that undermines the security of network infrastructure devices. This vulnerability resides within the firmware upgrade page of the router's web interface, specifically in how the system handles release notes displayed during firmware updates. The issue enables attackers to inject malicious scripts through spoofed release notes, creating a persistent threat vector that can compromise user sessions and network integrity.
The technical flaw manifests as insufficient input validation and output encoding within the router's web interface components responsible for displaying firmware release information. When users navigate to the firmware upgrade page, the system retrieves and displays release notes without proper sanitization of user-controllable input data. This weakness allows attackers to craft malicious release notes containing embedded javascript payloads that execute in the context of the authenticated user's browser session. The vulnerability directly maps to CWE-79 Cross-site Scripting, which is categorized under the broader weakness of improper neutralization of input during web page generation.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with potential access to sensitive administrative functions within the router's web interface. An attacker who successfully exploits this vulnerability can manipulate the display of firmware release notes to inject malicious code that could steal session cookies, redirect users to phishing sites, or even execute arbitrary commands within the router's administrative context. This risk is particularly severe given that the affected routers are consumer-grade devices that often lack robust security configurations and may be deployed in home or small office environments where network security is paramount.
The exploitation of this vulnerability aligns with ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, demonstrating how attackers can leverage web-based scripting languages to compromise network devices. The attack surface is further expanded by the fact that these routers are typically accessed through local network connections, making them vulnerable to both local and remote exploitation scenarios. Network administrators should consider this vulnerability as part of a broader attack chain that could lead to complete network compromise, particularly when combined with other vulnerabilities or through social engineering tactics that convince users to accept malicious firmware updates.
Mitigation strategies for CVE-2020-15499 should prioritize immediate firmware updates to version 3.0.0.4.385_20253 or later, which contain proper input validation and output encoding mechanisms to prevent malicious script injection. Network administrators should also implement network segmentation to limit access to router management interfaces, enforce strong authentication mechanisms, and regularly audit router configurations to ensure no unauthorized changes have occurred. Additionally, organizations should deploy web application firewalls that can detect and block suspicious script injection attempts, and consider implementing network monitoring solutions that can identify anomalous behavior patterns associated with XSS attacks targeting network infrastructure devices. The vulnerability serves as a reminder of the critical importance of keeping network equipment firmware updated, particularly for devices that form the foundation of network security infrastructure.