CVE-2021-22883 in NoSQL Database
Summary
by MITRE • 03/04/2021
Node.js before 10.24.0, 12.21.0, 14.16.0, and 15.10.0 is vulnerable to a denial of service attack when too many connection attempts with an 'unknownProtocol' are established. This leads to a leak of file descriptors. If a file descriptor limit is configured on the system, then the server is unable to accept new connections and prevent the process also from opening, e.g. a file. If no file descriptor limit is configured, then this lead to an excessive memory usage and cause the system to run out of memory.
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Analysis
by VulDB Data Team • 02/15/2025
The vulnerability described in CVE-2021-22883 represents a significant denial of service weakness in Node.js versions prior to specific patches. This flaw manifests when an attacker establishes numerous connection attempts using an unknown protocol, creating a condition where file descriptors become leaked within the system. The underlying technical mechanism involves the Node.js runtime failing to properly manage and release file descriptors associated with these malformed connection attempts, leading to resource exhaustion that can cripple the entire service.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader system stability concerns. When file descriptors accumulate without proper cleanup, the system eventually reaches its configured limits, preventing the server from accepting new connections or even opening basic files required for normal operation. This creates a cascading failure scenario where legitimate users cannot access services while the system becomes increasingly unstable. The vulnerability is particularly dangerous because it can be exploited with minimal resources, making it an attractive target for attackers seeking to disrupt services without requiring sophisticated attack infrastructure.
From a cybersecurity perspective, this vulnerability aligns with CWE-404, which describes improper resource management leading to resource exhaustion. The flaw also maps to ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion. The attack vector is particularly insidious because it doesn't require authentication or complex exploitation techniques, making it accessible to a wide range of threat actors. The memory consumption aspect of this vulnerability means that even systems without explicit file descriptor limits can become compromised through excessive memory usage, potentially leading to complete system crashes or unresponsiveness.
The remediation strategy centers on upgrading to patched versions of Node.js, specifically versions 10.24.0, 12.21.0, 14.16.0, and 15.10.0, which contain the necessary fixes to properly handle connection attempts with unknown protocols. System administrators should also implement monitoring for unusual connection patterns and establish appropriate file descriptor limits to mitigate potential impact even if the vulnerability is not immediately patched. Additionally, network-level protections such as rate limiting and connection throttling can provide defense-in-depth measures against exploitation attempts. Organizations should conduct thorough testing of patched environments to ensure that the updates don't introduce compatibility issues with existing applications while maintaining proper resource management practices.