CVE-2011-5037 in Google
Summary
by MITRE
Google V8 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters, as demonstrated by attacks against Node.js.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 08/08/2024
The vulnerability described in CVE-2011-5037 represents a critical hash collision issue within Google V8 JavaScript engine that affects Node.js applications and other systems relying on V8 for web processing. This flaw exists in the hash table implementation used to store form parameters, where the hash computation algorithm does not adequately protect against predictable collision attacks. The vulnerability specifically targets the hash function used in V8's internal data structures, creating a pathway for malicious actors to exploit the system's hashing mechanism through carefully crafted input parameters.
The technical implementation of this vulnerability stems from the weak hash function used in V8's parameter handling system, which allows attackers to craft specific form parameters that will consistently map to the same hash bucket. When these collision-inducing parameters are submitted in large quantities, the hash table degrades from optimal O(1) lookup performance to O(n) behavior, where n represents the number of colliding elements. This degradation causes the system to spend exponentially increasing amounts of CPU time processing each additional parameter, leading to significant performance degradation and ultimately system exhaustion. The vulnerability operates at the fundamental level of data structure implementation, specifically targeting the hash table collision resolution mechanism as defined by CWE-327.
From an operational impact perspective, this vulnerability enables remote attackers to execute successful denial of service attacks against Node.js applications and any system using V8's hash table implementation for parameter processing. The attack requires minimal resources to execute and can be automated, making it particularly dangerous in production environments where resource exhaustion can lead to complete service interruption. The CPU consumption pattern follows a predictable curve where each additional colliding parameter exponentially increases processing time, allowing attackers to consume system resources rapidly. This vulnerability directly maps to ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of algorithmic complexity exploitation.
Mitigation strategies for this vulnerability require immediate patching of affected Node.js versions and V8 engine implementations to address the underlying hash function weaknesses. System administrators should implement parameter validation and rate limiting mechanisms to prevent excessive parameter submission, while also monitoring for unusual CPU consumption patterns that may indicate hash collision attacks. The fix typically involves strengthening the hash function to resist predictable collision attacks, often through the implementation of randomized hash functions or the use of more robust cryptographic hash algorithms. Organizations should also consider implementing input sanitization processes that can detect and reject suspicious parameter patterns that may be designed to trigger hash collisions, providing defense-in-depth protection against similar vulnerabilities in other systems.