CVE-2017-6693 in Elastic Services Controller
Summary
by MITRE
A vulnerability in the ConfD server component of Cisco Elastic Services Controllers could allow an authenticated, local attacker to access information stored in the file system of an affected system, aka Unauthorized Directory Access. More Information: CSCvd76286. Known Affected Releases: 2.2(9.76) 2.3(1).
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6693 represents a critical authorization flaw within Cisco Elastic Services Controllers' ConfD server component, specifically manifesting as an unauthorized directory access issue that enables authenticated local attackers to gain illicit access to sensitive filesystem information. This vulnerability resides in the server-side configuration management system that governs how the Elastic Services Controller handles file system operations and access controls. The affected versions 2.2(9.76) and 2.3(1) demonstrate that this weakness persisted across multiple release streams, indicating a fundamental architectural flaw in the access control implementation. The vulnerability's classification under CWE-284 (Improper Access Control) reflects the core issue where the system fails to properly enforce access restrictions on directory operations, allowing local users with authentication credentials to bypass normal security boundaries. The attack vector requires local authentication, meaning that an adversary must first establish valid credentials to the system before exploiting this weakness, but the privilege escalation aspect remains significant as the authenticated access enables access to otherwise restricted file system areas.
The technical implementation of this vulnerability stems from inadequate validation of directory access requests within the ConfD server component, which processes configuration data and manages system resources. When legitimate authenticated users make requests to access specific directories or files, the system fails to properly verify that these access requests remain within appropriate boundaries. This flaw likely manifests through improper input validation or insufficient privilege checking mechanisms that should normally enforce access control policies. The vulnerability's impact extends beyond simple file access as it potentially exposes system configuration files, log data, and other sensitive information that could aid in further exploitation attempts or provide insight into the system's internal structure. The nature of the flaw suggests that the system may not properly sanitize or validate directory paths, allowing attackers to traverse filesystem structures using relative path references or other manipulation techniques that bypass normal access controls. This issue directly relates to ATT&CK technique T1078.004 (Valid Accounts: Local Accounts) as it leverages legitimate authentication credentials to access system resources, and T1083 (File and Directory Discovery) as it enables unauthorized access to file system structures.
The operational impact of CVE-2017-6693 extends beyond immediate information disclosure to potentially enable more sophisticated attacks within the compromised environment. Local attackers who successfully exploit this vulnerability can access system configuration files that may contain sensitive parameters, database connection strings, or other administrative information that could facilitate further compromise. The exposure of filesystem information could also reveal system architecture details, software versions, and operational patterns that attackers might use to plan subsequent attacks or tailor their exploitation strategies. Organizations running affected Cisco Elastic Services Controllers face significant risk as this vulnerability could provide attackers with access to system internals that might otherwise remain hidden. The presence of this flaw in multiple release versions suggests that the vulnerability was not properly addressed in security updates, potentially leaving deployed systems in production environments at risk. The combination of local authentication requirements with the potential for extensive filesystem access creates a dangerous scenario where a compromised local account could provide attackers with substantial information gathering capabilities that could lead to privilege escalation or lateral movement within the network infrastructure.
Mitigation strategies for CVE-2017-6693 should prioritize immediate patching of affected systems to the latest available software versions that contain security fixes for this vulnerability. Cisco has released security advisories addressing this issue, and organizations must ensure that all affected Cisco Elastic Services Controllers are updated to patched versions. System administrators should also implement additional monitoring of filesystem access patterns and authentication events to detect potential exploitation attempts. The principle of least privilege should be enforced more strictly by reviewing and limiting local user account permissions to minimize the potential impact if accounts are compromised. Network segmentation and access control measures can help contain the impact of potential exploitation by limiting lateral movement capabilities. Security teams should also conduct comprehensive audits of system configurations to identify any other potential access control weaknesses that could compound the risk from this vulnerability. Regular security assessments and penetration testing should be performed to validate that access controls are properly enforced and that no similar flaws exist in other system components. The vulnerability's classification as a local access issue means that traditional network-based security controls may not prevent exploitation, emphasizing the importance of host-based security measures and privileged access management. Organizations should also consider implementing automated vulnerability scanning tools that can detect the presence of unpatched systems and alert administrators to potential exposure to this and similar vulnerabilities.