CVE-2015-7371 in Adserver
Summary
by MITRE
Revive Adserver before 3.2.2 does not restrict access to run-mpe.php, which allows remote attackers to run the Maintenance Priority Engine and possibly cause a denial of service (resource consumption) via a direct request.
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Analysis
by VulDB Data Team • 06/21/2022
The vulnerability identified as CVE-2015-7371 affects Revive Adserver versions prior to 3.2.2, representing a critical access control flaw that undermines the application's security posture. This issue stems from insufficient authorization checks within the application's architecture, specifically concerning the run-mpe.php script which serves as the Maintenance Priority Engine component. The vulnerability manifests when remote attackers can directly access this script without proper authentication or authorization mechanisms, creating an unauthorized execution path that bypasses normal application security controls.
The technical exploitation of this vulnerability occurs through direct HTTP requests to the run-mpe.php endpoint, which triggers the Maintenance Priority Engine functionality. This engine is designed to handle various maintenance tasks including database optimization and resource cleanup operations. However, when accessible without proper restrictions, attackers can invoke these processes at will, potentially consuming excessive system resources such as memory, cpu cycles, and database connections. The resource consumption aspect directly maps to the denial of service threat model, where sustained exploitation can lead to application unavailability and system instability.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues in software applications. The flaw represents a classic case of insufficient authorization checking where the application fails to verify that incoming requests originate from legitimate administrative sources. The absence of proper authentication mechanisms for critical maintenance functions creates an attack surface that adversaries can leverage for system disruption. The vulnerability also intersects with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, as the exploitation directly targets system resources to cause service disruption.
The operational impact of CVE-2015-7371 extends beyond simple denial of service conditions to potentially compromise the entire ad serving infrastructure. When the Maintenance Priority Engine executes without proper controls, it can trigger cascading resource consumption that affects not only the targeted application but also underlying systems such as databases and web servers. This resource exhaustion can lead to degraded performance, application crashes, and in severe cases, complete system outages that disrupt advertising delivery and revenue generation for organizations relying on the platform. The vulnerability's severity is compounded by its ease of exploitation, as attackers require no specialized tools or deep technical knowledge beyond basic web browsing capabilities.
Organizations affected by this vulnerability should immediately implement mitigations including access control restrictions for the run-mpe.php endpoint, proper authentication enforcement, and network-level protections such as firewall rules that limit access to administrative scripts. The recommended solution involves upgrading to Revive Adserver version 3.2.2 or later, which includes proper authorization controls for maintenance functions. Additionally, implementing web application firewalls and monitoring for unauthorized access attempts to maintenance endpoints can provide additional layers of defense. Security teams should also conduct comprehensive audits of all administrative scripts and endpoints to identify similar access control vulnerabilities that may exist within the application ecosystem and related systems.