CVE-2018-5353 in ADSelfService Plus
Summary
by MITRE • 10/04/2020
The custom GINA/CP module in Zoho ManageEngine ADSelfService Plus before 5.5 build 5517 allows remote attackers to execute code and escalate privileges via spoofing. It does not authenticate the intended server before opening a browser window. An unauthenticated attacker capable of conducting a spoofing attack can redirect the browser to gain execution in the context of the WinLogon.exe process. If Network Level Authentication is not enforced, the vulnerability can be exploited via RDP. Additionally, if the web server has a misconfigured certificate then no spoofing attack is required
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Analysis
by VulDB Data Team • 11/14/2020
The vulnerability identified as CVE-2018-5353 affects Zoho ManageEngine ADSelfService Plus versions prior to 5.5 build 5517 and represents a critical privilege escalation flaw rooted in the implementation of custom GINA/CP modules. This vulnerability operates through a fundamental failure in authentication mechanisms within the Windows authentication framework, specifically targeting the WinLogon.exe process execution context. The flaw stems from the absence of proper server authentication before browser window initialization, creating an avenue for remote code execution that can be exploited by unauthenticated attackers. The technical implementation relies on the manipulation of browser navigation sequences within the authentication flow, where spoofing attacks can redirect user interactions to malicious endpoints that execute within the privileged WinLogon.exe context. This vulnerability directly maps to CWE-284 Access Control Issues and CWE-352 Cross-Site Request Forgery, as it involves improper access control mechanisms and unauthorized manipulation of browser requests. The attack vector leverages the trust relationship between the client and server components, exploiting the lack of certificate validation and server authentication protocols that should normally prevent such unauthorized interactions. The exploitation scenario becomes particularly dangerous when considering that the vulnerability can be triggered through RDP connections when Network Level Authentication is not enforced, providing attackers with multiple attack surfaces to target.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and privilege escalation capabilities. When successfully exploited, attackers can execute arbitrary code with the highest privileges available to the WinLogon.exe process, effectively gaining SYSTEM-level access to the target system. The privilege escalation occurs because WinLogon.exe operates with elevated privileges during the authentication process, making it a prime target for malicious code injection. The vulnerability's exploitation does not require authentication credentials, making it particularly dangerous as it can be leveraged by attackers who have no prior access to the system. The attack becomes even more severe when considering that misconfigured certificates on the web server can eliminate the need for spoofing attacks entirely, allowing direct exploitation without the prerequisite of man-in-the-middle conditions. This characteristic transforms what might initially appear as a browser-based vulnerability into a more insidious threat that can be exploited through various network access points. The vulnerability's impact is further amplified by its ability to bypass traditional authentication mechanisms, potentially allowing attackers to establish persistent access to systems without detection, as the malicious code executes within the legitimate Windows authentication framework.
Mitigation strategies for CVE-2018-5353 require a multi-layered approach addressing both the immediate software vulnerability and underlying security architecture weaknesses. The primary recommendation involves upgrading to Zoho ManageEngine ADSelfService Plus version 5.5 build 5517 or later, which includes proper authentication mechanisms and server verification protocols that prevent the spoofing conditions necessary for exploitation. Organizations should also implement strict certificate validation policies and ensure that all web servers maintain properly configured SSL/TLS certificates to prevent certificate-based bypasses of the authentication flow. Network-level protections should include enforcing Network Level Authentication (NLA) for all RDP connections, as this prevents the vulnerability from being exploited through remote desktop protocol access. Security configurations must also address the GINA/CP module implementation by either disabling custom modules or ensuring they properly validate server authenticity before initiating browser interactions. Additional protective measures include implementing network segmentation to limit access to the affected systems, deploying web application firewalls to monitor and filter suspicious browser navigation patterns, and establishing robust monitoring for unusual authentication flows that might indicate exploitation attempts. The mitigation strategy should also incorporate regular security assessments of authentication frameworks and certificate management processes to prevent similar vulnerabilities from emerging in other components of the authentication infrastructure, aligning with ATT&CK technique T1078 Valid Accounts and T1547 Boot or Logon Autostart Execution to prevent unauthorized access and persistent threats.