CVE-2014-0187 in Neutron
Summary
by MITRE
The openvswitch-agent process in OpenStack Neutron 2013.1 before 2013.2.4 and 2014.1 before 2014.1.1 allows remote authenticated users to bypass security group restrictions via an invalid CIDR in a security group rule, which prevents further rules from being applied.
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Analysis
by VulDB Data Team • 05/12/2026
The vulnerability identified as CVE-2014-0187 represents a critical flaw in the OpenStack Neutron networking component that affects the openvswitch-agent process. This security issue exists within OpenStack versions 2013.1 prior to 2013.2.4 and 2014.1 prior to 2014.1.1, creating a significant weakness in network security group enforcement mechanisms. The flaw specifically targets how the system processes security group rules, particularly when invalid CIDR (Classless Inter-Domain Routing) values are encountered within these rules. This vulnerability falls under the category of improper input validation and can be classified as CWE-20, which deals with improper input validation, and also relates to CWE-119, concerning weak buffer access controls. The issue enables malicious actors to manipulate network security policies through crafted network traffic that exploits the agent's handling of malformed CIDR specifications.
The technical exploitation of this vulnerability occurs when an authenticated attacker submits a security group rule containing an invalid CIDR value to the openvswitch-agent. This invalid CIDR specification causes the agent to skip processing subsequent security group rules, effectively creating a bypass mechanism that allows unauthorized network access. The flaw operates at the network policy enforcement layer where the system should be applying all configured rules in sequence to maintain proper security boundaries. When the agent encounters the malformed CIDR, it fails to properly validate the rule and instead proceeds to ignore any additional rules that would normally be applied to restrict network access. This creates a dangerous situation where network security policies can be circumvented simply by introducing one malformed rule that prevents rule evaluation from continuing properly.
The operational impact of CVE-2014-0187 extends beyond simple access control bypasses, as it fundamentally undermines the security model of OpenStack Neutron deployments. Organizations using affected versions face the risk of unauthorized network traffic passing through their virtualized environments, potentially allowing attackers to access resources they should not be permitted to reach. The vulnerability is particularly concerning because it requires only authenticated access to exploit, meaning that users with legitimate credentials could manipulate network policies to gain access to systems or data they should not be able to reach. This flaw could be leveraged as part of a broader attack chain where an attacker first gains access to a legitimate account and then uses this vulnerability to expand their access within the network infrastructure. The security implications align with ATT&CK technique T1068, which involves exploiting legitimate credentials to bypass security controls, and T1566, which covers social engineering attacks that can lead to credential compromise.
Organizations affected by this vulnerability should immediately implement patches to upgrade to versions 2013.2.4 or 2014.1.1, which contain the necessary fixes to properly validate CIDR specifications in security group rules. The mitigation strategy should also include enhanced monitoring of security group rule modifications and implementation of automated validation checks to detect malformed CIDR entries before they can be processed by the openvswitch-agent. Network administrators should consider implementing additional controls such as rule-based access controls and regular security audits to identify potential exploitation attempts. The fix implemented in the patched versions ensures that the agent properly validates all CIDR specifications and does not skip subsequent rules when encountering invalid values, maintaining the integrity of the security policy enforcement mechanism. This vulnerability serves as a reminder of the importance of proper input validation in network security systems and the critical nature of maintaining up-to-date security patches in cloud infrastructure deployments.