CVE-2021-3654 in Nova
Summary
by MITRE • 03/03/2022
A vulnerability was found in openstack-nova's console proxy, noVNC. By crafting a malicious URL, noVNC could be made to redirect to any desired URL.
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Analysis
by VulDB Data Team • 03/06/2022
The vulnerability identified as CVE-2021-3654 resides within the openstack-nova console proxy component known as noVNC, which serves as a web-based console interface for managing virtual machines within OpenStack environments. This flaw represents a critical security weakness that directly impacts the integrity and confidentiality of cloud infrastructure deployments relying on OpenStack's virtualization capabilities. The vulnerability stems from insufficient input validation and sanitization within the URL handling mechanisms of the noVNC component, creating a pathway for malicious actors to manipulate the redirection behavior of the console proxy.
The technical exploitation of this vulnerability occurs through the manipulation of URL parameters that control the redirection logic within noVNC. When a user accesses a maliciously crafted URL, the noVNC component fails to properly validate the destination parameter, allowing attackers to inject arbitrary URLs that will be processed as legitimate redirection targets. This flaw falls under the category of insecure redirection as defined by CWE-601, where the application's redirect functionality can be exploited to direct users to malicious domains. The vulnerability specifically impacts the web-based console functionality that enables administrators and users to interact with virtual machine consoles through a browser interface, making it particularly dangerous in multi-tenant cloud environments where unauthorized access to other domains could compromise entire infrastructure segments.
The operational impact of CVE-2021-3654 extends beyond simple phishing attacks, as it provides attackers with a mechanism to potentially escalate privileges and gain unauthorized access to cloud resources. In a typical OpenStack deployment, this vulnerability could enable an attacker to redirect users to malicious domains that might be used for credential harvesting, malware delivery, or further exploitation of the cloud environment. The attack vector is particularly concerning because it can be executed through seemingly legitimate console access points, making detection more difficult and potentially allowing attackers to remain undetected while establishing persistent access to cloud infrastructure. This vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to initial access through web-based attacks and privilege escalation via compromised administrative interfaces.
Organizations utilizing OpenStack deployments with nova console proxy functionality face significant risk from this vulnerability, as it can be exploited by both external attackers and compromised internal users. The attack surface is broad given that many cloud environments expose console interfaces to multiple user roles, including administrators who may have elevated privileges. Security measures should include immediate patching of affected openstack-nova installations, implementation of network-level controls to monitor and restrict outbound connections from console proxy components, and comprehensive monitoring of URL access patterns within console interfaces. Additionally, organizations should consider implementing web application firewalls to filter malicious URL parameters and establish strict access controls for console proxy functionality. The vulnerability demonstrates the critical importance of input validation and the principle of least privilege in cloud infrastructure components, as proper sanitization of user-provided URLs could have prevented this security breach.