CVE-2017-6683 in Elastic Services Controller
Summary
by MITRE
A vulnerability in the esc_listener.py script of Cisco Elastic Services Controllers could allow an authenticated, remote attacker to execute arbitrary commands as the tomcat user on an affected system, aka an Authentication Request Processing Arbitrary Command Execution Vulnerability. More Information: CSCvc76642. Known Affected Releases: 2.2(9.76).
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6683 resides within the esc_listener.py script of Cisco Elastic Services Controllers, representing a critical authentication request processing flaw that enables authenticated remote attackers to execute arbitrary commands with tomcat user privileges. This issue manifests as a command injection vulnerability where malicious input passed through authentication requests can be processed and executed by the underlying system. The vulnerability specifically affects Cisco Elastic Services Controllers version 2.2(9.76) and potentially other releases within the same software lineage. The flaw stems from insufficient input validation and sanitization mechanisms within the esc_listener.py component, which processes authentication requests from remote clients without properly escaping or filtering user-supplied data before incorporating it into system commands.
The technical implementation of this vulnerability involves the improper handling of user authentication requests where the system accepts input parameters that are directly incorporated into command execution contexts. When an authenticated attacker submits specially crafted authentication requests containing malicious command sequences, the esc_listener.py script processes these inputs without adequate sanitization, leading to arbitrary code execution. This type of vulnerability falls under the CWE-77 category of Command Injection, specifically representing a variant where authentication processing components become attack vectors for remote code execution. The ATT&CK framework categorizes this under T1059.001 - Command and Scripting Interpreter, specifically focusing on the execution of system commands through legitimate interfaces. The exploitation requires only authentication credentials, making it particularly dangerous as it can be leveraged by both internal and external attackers who have gained access to legitimate user accounts.
The operational impact of this vulnerability extends beyond simple command execution, as the tomcat user typically possesses significant system privileges within the application container environment. This allows attackers to potentially access sensitive data, modify system configurations, escalate privileges further within the environment, or establish persistent access through the compromised tomcat service. The vulnerability's remote nature means that attackers can exploit it from outside the network perimeter without requiring physical access or additional attack vectors. Organizations using affected Cisco Elastic Services Controllers may face unauthorized data access, system compromise, and potential lateral movement within their network infrastructure. The vulnerability also impacts the integrity and availability of the services provided by the controller, potentially leading to service disruption and data loss incidents.
Mitigation strategies for CVE-2017-6683 should prioritize immediate patching of affected systems with the latest Cisco security updates, as the vendor has released fixes specifically addressing this vulnerability. Network segmentation and access controls should be implemented to limit the exposure of affected systems to untrusted networks, while monitoring should be enhanced to detect suspicious authentication patterns or command execution attempts. Security teams should also implement proper input validation procedures and regularly audit authentication processing components for similar vulnerabilities. The implementation of principle of least privilege should ensure that the tomcat user has minimal required permissions, reducing the potential impact of successful exploitation. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other potentially affected components within their Cisco Elastic Services Controller deployments and ensure proper configuration management practices are maintained throughout their infrastructure.