CVE-2021-34707 in Evolved Programmable Network Manager
Summary
by MITRE • 08/05/2021
A vulnerability in the REST API of Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker to access sensitive data on an affected system. This vulnerability exists because the application does not sufficiently protect sensitive data when responding to an API request. An attacker could exploit the vulnerability by sending a specific API request to the affected application. A successful exploit could allow the attacker to obtain sensitive information about the application.
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Analysis
by VulDB Data Team • 08/08/2021
The vulnerability identified as CVE-2021-34707 represents a critical data exposure issue within Cisco Evolved Programmable Network Manager's REST API implementation. This weakness resides in the application's insufficient protection mechanisms for sensitive data during API response handling, creating a pathway for authenticated remote attackers to access confidential information. The vulnerability specifically targets the REST API interface of EPNM, which serves as the primary communication channel for network management operations and configuration data. Attackers exploiting this flaw can leverage specially crafted API requests to bypass normal access controls and retrieve sensitive data that should remain protected within the system. The issue stems from inadequate input validation and output sanitization within the API response processing logic, allowing unauthorized data disclosure through seemingly legitimate API interactions.
The technical exploitation of this vulnerability requires an attacker to possess valid authentication credentials for the EPNM system, as the flaw specifically targets authenticated access rather than unauthenticated attacks. This authentication requirement places the vulnerability in the context of privilege escalation and lateral movement within network management systems. The attack vector operates through the REST API interface where the application fails to properly sanitize or restrict sensitive data in response payloads. According to CWE classification, this vulnerability maps to CWE-200: Information Exposure, which encompasses various scenarios where sensitive information is inadvertently exposed to unauthorized parties. The flaw essentially creates a data leakage channel where legitimate API responses contain more information than intended, potentially exposing configuration details, system information, or other sensitive operational data that should be restricted to authorized personnel only.
From an operational impact perspective, this vulnerability poses significant risks to network security infrastructure management. The exposure of sensitive data through the EPNM REST API could provide attackers with valuable intelligence for further exploitation attempts, including system configurations, network topology information, device credentials, or operational parameters. The affected environment typically includes enterprise network management systems where EPNM serves as a central management platform for network devices and services. This vulnerability directly impacts the confidentiality aspect of the CIA triad, as unauthorized data access compromises the protection of sensitive information. The potential for cascading security impacts exists since the exposed data could reveal network architecture details that facilitate more sophisticated attacks. Organizations using EPNM systems face elevated risk of targeted attacks that leverage the disclosed information for privilege escalation, network reconnaissance, or system compromise attempts.
Security professionals should consider this vulnerability in the context of ATT&CK framework's T1083: File and Directory Discovery and T1069: Permission Groups Discovery techniques, as the exposure of sensitive data aligns with reconnaissance activities that attackers use to understand system configurations and access controls. Mitigation strategies should focus on implementing proper access controls, input validation, and output filtering within the REST API response handling logic. Organizations should immediately apply available vendor patches and updates to address the vulnerability. Additional defensive measures include implementing API rate limiting, monitoring for unusual API request patterns, and conducting regular security assessments of REST API endpoints. Network segmentation and principle of least privilege access controls should be enforced to limit the potential impact of successful exploitation attempts. The vulnerability also underscores the importance of proper security testing and code review processes for API implementations, particularly those handling sensitive operational data. Regular security audits of network management interfaces are essential to identify similar exposure risks and maintain robust security postures across critical infrastructure systems.