CVE-2017-6696 in Elastic Services Controller
Summary
by MITRE
A vulnerability in the file system of Cisco Elastic Services Controllers could allow an authenticated, local attacker to gain access to sensitive user credentials that are stored in an affected system. More Information: CSCvd73677. Known Affected Releases: 2.3(2).
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6696 represents a critical local privilege escalation issue within Cisco Elastic Services Controllers version 2.3(2) and potentially other affected releases. This flaw resides in the file system implementation of the controller software, creating an avenue for authenticated attackers who already possess legitimate credentials to escalate their privileges and access sensitive information. The vulnerability specifically targets the storage mechanisms used by the system to maintain user credentials, exposing a fundamental weakness in the access control and data protection measures implemented within the platform.
The technical implementation of this vulnerability stems from inadequate file system permissions and access controls that fail to properly restrict access to credential storage locations. An attacker with valid authentication credentials can exploit this weakness to navigate to restricted directories where user authentication data is stored in plain text or with insufficient encryption. This represents a classic case of insufficient privilege separation and weak access controls that violate established security principles. The flaw operates at the operating system level where proper file system permissions should prevent unauthorized access to sensitive data repositories, yet the implementation fails to enforce these protections effectively.
From an operational perspective, the impact of this vulnerability extends beyond simple credential theft to potentially compromise entire network infrastructures managed by the affected controllers. When authenticated local attackers can extract user credentials, they gain the ability to move laterally within the network, access additional systems, and potentially escalate their privileges to administrative levels. The vulnerability creates a persistent threat vector that can be exploited repeatedly once the initial access is established, making it particularly dangerous for environments where the controller serves as a central management point for network services. This aligns with ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing, as the initial access often comes through legitimate authentication mechanisms that are then exploited for further compromise.
The security implications of this vulnerability are particularly severe given that it requires only local authentication to exploit, meaning that any user with legitimate access to the system can potentially leverage this weakness. This makes the attack surface significantly larger compared to remote exploitation vectors, as the attacker only needs to establish a local session rather than overcoming network-level defenses. The vulnerability also demonstrates poor adherence to the principle of least privilege, where sensitive credential storage should be protected by multiple layers of security controls that prevent unauthorized access regardless of the attacker's initial privilege level. Organizations relying on Cisco Elastic Services Controllers in production environments face significant risk of credential compromise and potential system takeover if this vulnerability remains unpatched.
Mitigation strategies for CVE-2017-6696 should prioritize immediate deployment of Cisco's official security patches and updates that address the file system access control weaknesses. System administrators must conduct thorough vulnerability assessments to identify all affected controllers and ensure proper patch management protocols are implemented. Additional protective measures include implementing strict file system permissions, monitoring access to credential storage directories, and establishing robust audit logging to detect unauthorized access attempts. The vulnerability highlights the importance of regular security assessments and proper configuration management practices that align with industry standards such as those outlined in the CWE database under categories related to insufficient privilege separation and improper access control. Organizations should also consider implementing network segmentation and additional monitoring controls to detect potential exploitation attempts and limit the lateral movement capabilities of compromised accounts.