CVE-2017-11499 in Node.js
Summary
by MITRE
Node.js v4.0 through v4.8.3, all versions of v5.x, v6.0 through v6.11.0, v7.0 through v7.10.0, and v8.0 through v8.1.3 was susceptible to hash flooding remote DoS attacks as the HashTable seed was constant across a given released version of Node.js. This was a result of building with V8 snapshots enabled by default which caused the initially randomized seed to be overwritten on startup.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-11499 represents a critical denial of service weakness in Node.js versions spanning multiple release lines including v4.x through v4.8.3, v5.x, v6.x through v6.11.0, v7.x through v7.10.0, and v8.x through v8.1.3. This issue stems from the predictable nature of hash table seeds used by the underlying V8 JavaScript engine, creating a systematic weakness that adversaries could exploit to perform hash flooding attacks. The vulnerability specifically affects systems where Node.js is built with V8 snapshots enabled by default, a configuration that inadvertently resets the initially randomized hash seed during application startup, thereby eliminating the security benefits of randomization.
The technical flaw manifests in the way Node.js handles hash table implementations within its V8 engine, where the hash seed value remains constant across all instances of a given Node.js version. This predictable behavior enables attackers to craft specific inputs that will consistently cause hash collisions, leading to degraded performance or complete system unresponsiveness. The vulnerability operates at the core of the JavaScript engine's data structure management, where hash tables are used extensively for object property lookups, map operations, and various internal data processing tasks. When an attacker can predict the hash seed, they can construct inputs that will force hash table operations to degrade from optimal O(1) performance to worst-case O(n) behavior, effectively exhausting system resources and causing denial of service conditions.
The operational impact of this vulnerability extends beyond simple service disruption to encompass significant security implications for Node.js applications deployed in production environments. Attackers can leverage this weakness to perform remote denial of service attacks against Node.js servers without requiring any special privileges or authentication. The attack vector is particularly concerning because it targets the fundamental performance characteristics of the runtime environment, making it difficult to distinguish from legitimate high-load scenarios. Systems running vulnerable Node.js versions become susceptible to resource exhaustion attacks where malicious inputs can cause memory allocation spikes, CPU utilization increases, and overall system instability. The vulnerability affects all applications built on these Node.js versions regardless of their specific implementation or use case, creating a broad attack surface that spans web applications, API services, and server-side processing systems.
Mitigation strategies for CVE-2017-11499 require immediate version updates to patched Node.js releases where the hash seed randomization has been properly implemented. Organizations should prioritize upgrading to Node.js versions that have addressed this vulnerability through either disabling V8 snapshots by default or implementing proper seed randomization mechanisms. The fix addresses the underlying CWE-122 weakness related to improper handling of hash table seeds and aligns with ATT&CK technique T1499.001 for network denial of service. System administrators should also consider implementing input validation and rate limiting measures as additional defensive controls to reduce the impact of potential attacks. Additionally, monitoring systems should be configured to detect unusual patterns in hash table performance metrics and resource consumption that could indicate exploitation attempts. The vulnerability highlights the importance of understanding how runtime configuration choices can impact security properties, particularly in systems that rely heavily on hash-based data structures for performance optimization.