CVE-2020-8151 in Active Resource
Summary
by MITRE
There is a possible information disclosure issue in Active Resource <v5.1.1 that could allow an attacker to create specially crafted requests to access data in an unexpected way and possibly leak information.
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Analysis
by VulDB Data Team • 08/18/2025
The vulnerability identified as CVE-2020-8151 affects Active Resource versions prior to 5.1.1, representing a significant information disclosure weakness within Ruby on Rails applications. This flaw stems from inadequate input validation and sanitization mechanisms that fail to properly restrict access to application resources, creating potential pathways for unauthorized data exposure. The vulnerability resides in the way Active Resource handles HTTP requests and responses, particularly when processing crafted payloads that exploit improper parameter handling within the framework's resource management components.
The technical implementation of this vulnerability allows attackers to construct malicious requests that bypass normal access controls and authorization checks. When Active Resource processes these specially crafted inputs, it fails to properly validate or sanitize the request parameters, enabling attackers to manipulate the resource access patterns and potentially retrieve sensitive data that should remain protected. This issue manifests through improper handling of HTTP headers and request bodies that contain encoded or malformed data, which the framework does not adequately filter or reject. The vulnerability is classified under CWE-20 as "Improper Input Validation" and specifically relates to CWE-213 as "Information Exposure Through Inadvertent Data Leakage," highlighting the indirect nature of the information disclosure.
The operational impact of CVE-2020-8151 extends beyond simple data exposure, as it can enable attackers to perform reconnaissance activities and gather intelligence about application structure, data models, and potentially sensitive business logic. When exploited successfully, this vulnerability allows for privilege escalation scenarios where attackers can access data beyond their intended authorization levels, potentially compromising user accounts, confidential business information, or system configurations. The attack vector typically involves sending crafted HTTP requests that manipulate the resource identifiers or query parameters, causing the framework to return unexpected data responses. This vulnerability aligns with ATT&CK technique T1213.002 "Data from Information Repositories" and T1074.001 "Data Staged" as it enables attackers to harvest sensitive data through improper resource access controls.
Mitigation strategies for CVE-2020-8151 focus primarily on upgrading to Active Resource version 5.1.1 or later, which includes proper input validation and sanitization mechanisms. Organizations should implement comprehensive input filtering at multiple layers including application firewalls, API gateways, and within the application code itself. Network-level protections such as web application firewalls should be configured to detect and block suspicious request patterns that match known exploitation signatures. Additionally, implementing proper access control mechanisms, including role-based access controls and comprehensive logging of all resource access attempts, can help detect and prevent unauthorized data access. Security teams should conduct thorough code reviews focusing on parameter handling and input validation, particularly in areas where Active Resource components interact with external data sources. Regular security assessments and vulnerability scanning should be implemented to identify potential exploitation paths and ensure that all framework components remain up-to-date with security patches. The remediation process should also include comprehensive testing of access control mechanisms to validate that proper authorization checks are functioning correctly and that no unauthorized data access pathways remain available to attackers.