CVE-2018-9843 in Password Vault Web Access
Summary
by MITRE
The REST API in CyberArk Password Vault Web Access before 9.9.5 and 10.x before 10.1 allows remote attackers to execute arbitrary code via a serialized .NET object in an Authorization HTTP header.
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Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2018-9843 represents a critical remote code execution flaw within the REST API of CyberArk Password Vault Web Access software. This security weakness affects versions prior to 9.9.5 and 10.1, creating a significant risk for organizations relying on CyberArk's privileged access management solutions. The vulnerability stems from improper input validation and deserialization of untrusted data within the authentication mechanism, specifically in how the Authorization HTTP header is processed. Attackers can exploit this flaw by crafting malicious serialized .NET objects and injecting them into the Authorization header, thereby bypassing normal authentication controls and gaining unauthorized access to the system.
The technical exploitation of this vulnerability occurs through a deserialization attack pattern that falls under CWE-502, which specifically addresses the deserialization of untrusted data. When the REST API processes the Authorization header, it attempts to deserialize the serialized .NET object without adequate validation or sanitization of the input. This creates an opportunity for attackers to inject malicious code that executes with the privileges of the affected service. The attack vector is particularly dangerous because it operates at the application layer, allowing remote exploitation without requiring local access or prior authentication. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1078.004 for valid accounts, as successful exploitation can lead to persistent access and arbitrary code execution within the target environment.
The operational impact of CVE-2018-9843 extends beyond immediate code execution capabilities to encompass potential compromise of the entire privileged access management infrastructure. Organizations utilizing vulnerable versions of CyberArk Password Vault Web Access face risks including unauthorized access to sensitive credentials, privilege escalation attacks, and potential lateral movement within their network. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet, making it particularly attractive for automated attack campaigns. Successful exploitation can result in complete system compromise, data exfiltration, and disruption of critical privileged access management services. The attack surface is further expanded due to the widespread adoption of CyberArk solutions in enterprise environments, where these systems often serve as central repositories for critical credentials and access controls.
Organizations should immediately implement mitigation strategies including upgrading to the patched versions 9.9.5 and 10.1, which address the deserialization vulnerability through proper input validation and sanitization. Network segmentation and firewall rules should be implemented to restrict access to the REST API endpoints, particularly limiting exposure to internal networks only. Additional protective measures include monitoring for unusual patterns in Authorization header content and implementing intrusion detection systems that can identify potential exploitation attempts. The remediation process should also involve comprehensive security assessments of the affected systems, including code reviews and penetration testing to ensure no other similar vulnerabilities exist. Organizations should also consider implementing additional authentication controls and monitoring mechanisms to detect and prevent unauthorized access attempts to privileged accounts. Regular security updates and patch management processes should be strengthened to prevent similar vulnerabilities from occurring in the future, as this incident demonstrates the critical importance of secure deserialization practices in web applications.