CVE-2011-4076 in OpenStack Nova
Summary
by MITRE
OpenStack Nova before 2012.1 allows someone with access to an EC2_ACCESS_KEY (equivalent to a username) to obtain the EC2_SECRET_KEY (equivalent to a password). Exposing the EC2_ACCESS_KEY via http or tools that allow man-in-the-middle over https could allow an attacker to easily obtain the EC2_SECRET_KEY. An attacker could also presumably brute force values for EC2_ACCESS_KEY.
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Analysis
by VulDB Data Team • 02/28/2024
The vulnerability identified as CVE-2011-4076 represents a critical security flaw in OpenStack Nova versions prior to 2012.1 that fundamentally compromises the authentication mechanism for EC2-compatible API access. This issue stems from improper handling of credential exposure within the cloud infrastructure management platform, where the EC2_ACCESS_KEY serves as a username equivalent and the EC2_SECRET_KEY functions as the corresponding password. The flaw creates a direct pathway for unauthorized parties to escalate their privileges and gain full access to cloud resources through the compromised authentication tokens.
The technical implementation of this vulnerability occurs due to insufficient protection mechanisms for EC2_ACCESS_KEY values during transmission and storage within the Nova service. When these access keys are exposed via HTTP communications or transmitted through tools that fail to properly secure HTTPS connections, attackers can intercept and extract the associated EC2_SECRET_KEY values. This represents a classic credential exposure vulnerability that violates fundamental security principles of authentication token protection. The flaw operates at the application layer and affects the integrity of the authentication system, making it particularly dangerous as it allows attackers to impersonate legitimate users within the cloud environment.
The operational impact of this vulnerability extends far beyond simple credential theft, as it provides attackers with complete administrative access to cloud resources managed by OpenStack Nova. Once an attacker obtains a valid EC2_ACCESS_KEY and its corresponding EC2_SECRET_KEY, they can perform any action permitted by the user account, including creating, modifying, or deleting virtual machines, accessing stored data, and manipulating network configurations. This vulnerability essentially eliminates the security boundary between legitimate users and potential attackers, as the compromised credentials grant full access to the cloud infrastructure. The risk is compounded by the fact that attackers could potentially brute force EC2_ACCESS_KEY values, making the attack surface significantly larger than initially apparent.
Mitigation strategies for CVE-2011-4076 require immediate implementation of proper HTTPS enforcement and certificate validation mechanisms throughout the OpenStack Nova deployment. Organizations must ensure all communications between clients and the Nova service occur exclusively over encrypted channels with proper certificate validation to prevent man-in-the-middle attacks. The implementation of secure credential storage practices and regular credential rotation procedures should be enforced, along with monitoring for unauthorized access attempts. Additionally, the deployment should be upgraded to OpenStack Nova version 2012.1 or later, which includes proper authentication token protection mechanisms. This vulnerability aligns with CWE-312 (Sensitive Data Exposure) and represents a critical weakness in the authentication architecture that directly maps to ATT&CK technique T1078 (Valid Accounts) and T1566 (Phishing). Organizations should implement network segmentation and access controls to limit exposure, while also establishing robust monitoring for credential access patterns that could indicate exploitation attempts.