CVE-2018-1163 in NetVault Backup
Summary
by MITRE
This vulnerability allows remote attackers to bypass authentication on vulnerable installations of Quest NetVault Backup 11.2.0.13. The specific flaw exists within JSON RPC Request handling. By setting the checksession parameter to a specific value, it is possible to bypass authentication to critical functions. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-4752.
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Analysis
by VulDB Data Team • 01/03/2020
The vulnerability identified as CVE-2018-1163 represents a critical authentication bypass flaw in Quest NetVault Backup version 11.2.0.13, which operates under the Common Weakness Enumeration classification of CWE-287 - Improper Handling of Authentication Tokens. This issue specifically targets the JSON RPC request processing mechanism within the backup software, creating a pathway for unauthenticated attackers to access protected administrative functions. The vulnerability stems from insufficient validation of session parameters within the remote procedure call interface, allowing malicious actors to manipulate the checksession parameter to gain unauthorized access to the system. This authentication bypass occurs at the application layer and affects the core security controls that should prevent unauthorized access to critical backup management functions.
The technical exploitation of this vulnerability involves crafting specially formatted JSON RPC requests where the checksession parameter is manipulated to bypass the normal authentication flow. When an attacker sends a request with this specific parameter value, the system fails to properly validate the session state, allowing access to administrative functions that should require proper authentication credentials. This flaw operates at the interface level between the client application and the backup server, where the JSON RPC framework does not adequately enforce session validation. The vulnerability's impact is amplified because it allows attackers to perform operations that require SYSTEM level privileges, potentially enabling full system compromise. The issue demonstrates poor input validation and session management practices that violate fundamental security principles.
The operational impact of CVE-2018-1163 extends beyond simple unauthorized access, as it creates a potential gateway for more severe attacks within the network infrastructure. An attacker who successfully exploits this vulnerability can execute arbitrary code with SYSTEM privileges, effectively gaining complete control over the backup server. This level of access enables the attacker to modify backup configurations, access sensitive data stored in backup repositories, and potentially use the compromised system as a pivot point for attacking other network components. The vulnerability's remote exploitability means that attackers do not need physical access or local network presence to leverage this flaw, making it particularly dangerous in enterprise environments where backup servers often contain critical organizational data. The attack surface is further expanded by the fact that backup systems are frequently targeted due to the sensitive nature of the data they contain.
Mitigation strategies for this vulnerability should prioritize immediate patch application from Quest Software, as the vendor has released security updates to address the authentication bypass flaw. Organizations should implement network segmentation to limit access to backup systems, ensuring that only authorized administrative workstations can reach the backup server ports. Additional protective measures include implementing strict firewall rules that restrict JSON RPC access to trusted IP addresses and enabling comprehensive logging of all backup server activities for monitoring purposes. Security teams should also conduct thorough vulnerability assessments to identify any other potential authentication bypass opportunities within the backup infrastructure. The remediation process should include reviewing and strengthening session management protocols within the backup application, implementing proper input validation for all RPC parameters, and establishing regular security audits of backup system configurations. Organizations should consider deploying intrusion detection systems specifically configured to monitor for unusual patterns in backup server communications that might indicate exploitation attempts. This vulnerability highlights the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect critical infrastructure components like backup systems that often contain sensitive organizational data.