CVE-2014-7821 in Neutron
Summary
by MITRE
OpenStack Neutron before 2014.1.4 and 2014.2.x before 2014.2.1 allows remote authenticated users to cause a denial of service (crash) via a crafted dns_nameservers value in the DNS configuration.
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Analysis
by VulDB Data Team • 04/04/2022
The vulnerability identified as CVE-2014-7821 affects OpenStack Neutron networking components, specifically targeting versions prior to 2014.1.4 and 2014.2.1. This issue represents a critical denial of service weakness that can be exploited by authenticated remote attackers to crash the neutron service. The vulnerability stems from inadequate input validation within the DNS configuration handling mechanism, where the system fails to properly sanitize or validate dns_nameservers values provided by authenticated users. This flaw falls under the CWE-20 category for improper input validation, which is a fundamental security weakness that allows malicious inputs to disrupt normal system operations.
The technical implementation of this vulnerability occurs when an authenticated user submits a crafted dns_nameservers value that contains malformed or malicious data within the DNS configuration parameters. The neutron service processes this input without sufficient validation, leading to a crash condition that results in complete service disruption. This type of vulnerability represents a classic example of a buffer overflow or input parsing error that can be triggered through crafted network requests. The attack vector requires only authentication to the neutron service, making it particularly dangerous as it can be exploited by insiders or compromised accounts with legitimate access rights.
From an operational impact perspective, this vulnerability can severely compromise cloud infrastructure availability and reliability. When the neutron service crashes, it affects network connectivity for all virtual machines and services that depend on the affected networking components. The disruption can cascade across multiple tenants and applications within the OpenStack environment, potentially causing widespread service outages. The attack requires minimal resources and technical expertise to execute, making it particularly attractive to malicious actors seeking to disrupt cloud operations. This vulnerability directly impacts the availability aspect of the CIA triad and can be classified under the ATT&CK technique T1499 for network denial of service attacks.
Organizations affected by this vulnerability should immediately implement mitigation strategies including upgrading to patched versions of OpenStack Neutron, implementing input validation controls, and monitoring for suspicious DNS configuration changes. The recommended remediation involves applying the official patches released by OpenStack for versions 2014.1.4 and 2014.2.1, which include enhanced validation routines for dns_nameservers parameters. Network segmentation and access controls should be strengthened to limit the scope of potential exploitation, while implementing comprehensive logging and monitoring to detect anomalous configuration changes. Additionally, regular security assessments and penetration testing should be conducted to identify similar input validation weaknesses in other components of the cloud infrastructure. The vulnerability demonstrates the critical importance of input sanitization in cloud networking services and serves as a reminder of the need for robust security controls in distributed cloud environments.