CVE-2021-42853 in AppInternals Dynamic Sampling Agent
Summary
by MITRE • 03/10/2022
It was discovered that the SteelCentral AppInternals Dynamic Sampling Agent's (DSA) AgentDiagnosticServlet has directory traversal vulnerability at the "/api/appInternals/1.0/agent/diagnostic/logs" API. The affected endpoint does not have any input validation of the user's input that allows a malicious payload to be injected.
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Analysis
by VulDB Data Team • 03/13/2022
The vulnerability identified as CVE-2021-42853 affects the SteelCentral AppInternals Dynamic Sampling Agent implementation, specifically targeting the AgentDiagnosticServlet component within the application's API framework. This directory traversal flaw exists at the "/api/appInternals/1.0/agent/diagnostic/logs" endpoint, representing a critical security weakness that can be exploited by unauthorized actors to access sensitive system resources. The affected system is part of a network monitoring and application performance management solution that collects and processes diagnostic information from distributed application environments. The vulnerability stems from inadequate input validation mechanisms within the servlet implementation, creating an attack surface where malicious users can manipulate request parameters to navigate beyond the intended directory boundaries.
The technical nature of this vulnerability aligns with CWE-22, which defines path traversal or directory traversal flaws as weaknesses that occur when an application allows user input to influence file system access without proper validation. In this case, the AgentDiagnosticServlet fails to sanitize or validate the user-provided input parameters that are used to determine which log files or system resources should be accessed. Attackers can exploit this by crafting malicious requests that include directory traversal sequences such as "../" or similar path manipulation techniques to access files outside the intended directory structure. The absence of input validation creates a direct pathway for unauthorized file system access, potentially allowing attackers to retrieve sensitive log files, configuration data, or other system resources that should remain protected.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it can enable attackers to escalate their privileges and potentially gain deeper system control. An attacker who successfully exploits this vulnerability could access application logs that may contain sensitive information such as user credentials, system configurations, or business-critical data that is typically stored in log files. The attack surface is particularly concerning because the SteelCentral AppInternals solution is designed for enterprise environments where sensitive operational data flows through the system. This vulnerability could allow adversaries to gather intelligence about the target environment, potentially leading to further exploitation opportunities within the network infrastructure.
Organizations implementing the affected SteelCentral AppInternals Dynamic Sampling Agent should immediately implement mitigations to address this vulnerability. The primary remediation involves implementing proper input validation and sanitization for all user-provided parameters within the AgentDiagnosticServlet component. This includes implementing strict path validation that prevents directory traversal sequences from being processed, as well as implementing proper access controls that limit the scope of files that can be accessed through the API. Additionally, organizations should consider implementing network segmentation and API gateway controls to limit exposure of the vulnerable endpoint. The mitigation strategy should align with industry best practices for web application security and should follow the ATT&CK framework's guidance for defending against credential access and reconnaissance techniques that leverage directory traversal vulnerabilities. Regular security assessments and penetration testing should be conducted to verify that the implemented controls effectively prevent exploitation of this and similar vulnerabilities in the application's attack surface.