CVE-2020-7222 in Web Server
Summary
by MITRE
An issue was discovered in Amcrest Web Server 2.520.AC00.18.R 2017-06-29 WEB 3.2.1.453504. The login page responds with JavaScript when one tries to authenticate. An attacker who changes the result parameter (to true) in this JavaScript code can bypass authentication and achieve limited privileges (ability to see every option but not modify them).
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Analysis
by VulDB Data Team • 03/24/2024
This vulnerability resides in the Amcrest Web Server version 2.520.AC00.18.R released on 2017-06-29 with WEB version 3.2.1.453504, representing a critical authentication bypass flaw that fundamentally compromises the security posture of affected devices. The issue manifests through the login page's improper handling of authentication responses, where the server returns JavaScript code instead of proper HTTP status codes during the authentication process. This design flaw creates a pathway for attackers to manipulate the authentication flow by directly modifying the result parameter within the returned JavaScript code to true, effectively circumventing the standard authentication mechanism.
The technical implementation of this vulnerability stems from a lack of proper input validation and output encoding within the authentication response handling logic. When users attempt to log in, the server generates a JavaScript response that contains a result parameter indicating authentication success or failure. However, this parameter is not properly sanitized or validated on the client side, allowing attackers to modify it directly in the browser's memory or through proxy tools like burp suite. The vulnerability aligns with CWE-285, which addresses improper authorization, and specifically demonstrates how insufficient validation of authentication responses can lead to privilege escalation. The flaw operates at the application layer and can be categorized under ATT&CK technique T1078.004, which covers valid accounts used for lateral movement through legitimate authentication mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with a foothold that enables them to navigate the device's administrative interface and view all available options and settings. While the attacker cannot modify system configurations or make changes to device settings, the ability to observe all interface elements, configuration parameters, and system information creates significant risk for organizations relying on these security cameras and surveillance systems. This reconnaissance capability allows attackers to gather intelligence about the device's configuration, network settings, firmware versions, and potentially identify additional vulnerabilities or misconfigurations within the broader network infrastructure. The vulnerability affects the confidentiality and integrity aspects of the security model, as it enables unauthorized information disclosure while maintaining the device's operational integrity through read-only access.
Organizations should immediately implement mitigations including updating to the latest firmware versions provided by Amcrest, which likely address this authentication bypass vulnerability through proper input validation and secure authentication response handling. Network segmentation and access control measures should be enforced to limit direct access to these devices from untrusted networks, while implementing strong network monitoring to detect unusual authentication patterns or JavaScript code manipulation attempts. The use of network access control lists and firewall rules can restrict access to the web interface to only trusted administrative workstations. Additionally, organizations should consider implementing intrusion detection systems that can identify and alert on suspicious JavaScript manipulation activities. Regular security assessments and vulnerability scanning should be conducted to identify similar authentication bypass vulnerabilities in other networked devices, while maintaining up-to-date threat intelligence to detect exploitation attempts targeting this specific vulnerability. The remediation process should include comprehensive testing to ensure that authentication responses are properly handled and that no similar flaws exist in related web application components.