CVE-2025-0650 in ovn
Summary
by MITRE • 01/23/2025
A flaw was found in the Open Virtual Network (OVN). Specially crafted UDP packets may bypass egress access control lists (ACLs) in OVN installations configured with a logical switch with DNS records set on it and if the same switch has any egress ACLs configured. This issue can lead to unauthorized access to virtual machines and containers running on the OVN network.
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Analysis
by VulDB Data Team • 02/07/2025
The vulnerability identified as CVE-2025-0650 represents a critical security flaw within the Open Virtual Network framework that undermines the fundamental network isolation principles essential for virtualized environments. This weakness specifically targets the egress access control list implementation within OVN installations, creating a potential pathway for malicious actors to circumvent network security policies. The flaw manifests when carefully constructed UDP packets are processed by the network infrastructure, allowing traffic to bypass intended restrictions that should prevent unauthorized communication from virtual machines and containers.
The technical mechanism behind this vulnerability involves a specific interaction between DNS record configuration and egress ACL enforcement within logical switches. When a logical switch in OVN contains DNS records and has egress access control lists configured, the system fails to properly validate incoming UDP packets against the established security policies. This occurs because the packet processing logic does not adequately account for the presence of DNS records when evaluating egress restrictions, creating a bypass condition that allows malicious traffic to slip through security controls. The flaw essentially creates a race condition or logic error in the packet filtering mechanism where the DNS record processing takes precedence over ACL enforcement, resulting in the complete failure of egress controls.
The operational impact of this vulnerability extends beyond simple network access issues, potentially enabling sophisticated attack scenarios that could compromise entire virtualized infrastructures. Attackers could exploit this weakness to establish unauthorized communication channels between virtual machines, potentially exfiltrating sensitive data or establishing command and control connections. The vulnerability affects any OVN deployment where logical switches contain DNS records and have egress ACLs configured, making it particularly concerning for cloud environments, container orchestration platforms, and enterprise virtualization setups. This issue directly violates the principle of least privilege and network segmentation that security professionals rely upon to protect virtualized environments from lateral movement and data breaches.
Organizations implementing OVN solutions must urgently evaluate their network configurations to identify logical switches containing DNS records with egress ACLs, as these represent the most vulnerable components. The mitigation approach should focus on either disabling DNS record functionality on switches that require strict egress controls or implementing additional network monitoring to detect anomalous UDP traffic patterns. Security teams should also consider deploying network intrusion detection systems that can identify the specific UDP packet patterns associated with this vulnerability. From a compliance perspective, this vulnerability may impact organizations subject to standards such as iso 27001, pci dss, and nist cybersecurity framework, as it creates potential data exposure risks that could lead to regulatory violations. The issue aligns with attack techniques documented in the mitre att&ck framework under network penetration and privilege escalation categories, particularly targeting the network infrastructure layer where traditional endpoint security measures may not detect the bypassed traffic.
This vulnerability demonstrates the complexity of modern virtual networking solutions and the challenges in maintaining consistent security policies across different network components. The flaw highlights the importance of thorough testing for edge cases in security implementations and the need for comprehensive security reviews of virtual networking components. Organizations should also consider implementing network micro-segmentation strategies that provide additional layers of protection beyond traditional ACL mechanisms, ensuring that even if one security control is bypassed, other controls remain effective. The security community should closely monitor for similar vulnerabilities in other virtual networking solutions that may exhibit comparable logic errors in their packet processing and access control enforcement mechanisms.