CVE-2014-7847 in Moodle
Summary
by MITRE
iplookup/index.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allows remote attackers to cause a denial of service (resource consumption) by triggering the calculation of an estimated latitude and longitude for an IP address.
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Analysis
by VulDB Data Team • 04/04/2022
The vulnerability identified as CVE-2014-7847 affects Moodle versions up to 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3, specifically within the iplookup/index.php component. This issue represents a resource exhaustion attack vector that can lead to denial of service conditions, making it a significant concern for educational institutions relying on Moodle for their learning management systems. The vulnerability stems from the improper handling of IP address geolocation calculations, which can be exploited by remote attackers to consume excessive system resources.
The technical flaw occurs when the iplookup/index.php script processes IP address lookups and attempts to calculate estimated latitude and longitude coordinates for the provided addresses. This calculation process involves complex geolocation algorithms that require substantial computational resources and database queries. When an attacker submits malicious IP addresses or triggers multiple simultaneous lookup requests, the system becomes overwhelmed with resource-intensive geolocation calculations that can consume CPU cycles, memory, and database connections. The vulnerability is classified as a resource consumption issue under CWE-400, which specifically addresses excessive resource consumption that can lead to denial of service conditions.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire Moodle platform availability. Attackers can exploit this weakness by flooding the system with geolocation requests, causing legitimate users to experience slow response times or complete service unavailability. The resource exhaustion can affect database performance, application server capacity, and overall system responsiveness, making it particularly dangerous in educational environments where continuous access to learning materials is critical. This vulnerability aligns with ATT&CK technique T1499.004, which covers resource exhaustion attacks targeting availability through excessive resource consumption.
Organizations using affected Moodle versions should implement immediate mitigations to protect their systems from this vulnerability. The primary recommended action involves upgrading to patched versions of Moodle that address this specific resource consumption issue. Additionally, administrators should consider implementing rate limiting mechanisms on geolocation lookup requests to prevent abuse, configuring firewall rules to restrict access to the iplookup functionality, and monitoring system resources for unusual patterns that might indicate exploitation attempts. Network-level protections such as implementing API throttling and connection limits can provide additional defense in depth. The vulnerability demonstrates the importance of proper input validation and resource management in web applications, particularly those handling external data processing operations.