CVE-2015-7944 in Ganeti
Summary
by MITRE
The RESTful control interface (aka RAPI or ganeti-rapi) in Ganeti before 2.9.7, 2.10.x before 2.10.8, 2.11.x before 2.11.8, 2.12.x before 2.12.6, 2.13.x before 2.13.3, 2.14.x before 2.14.2, and 2.15.x before 2.15.2, when used in SSL mode, allows remote attackers to cause a denial of service (resource consumption) via SSL parameter renegotiation.
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Analysis
by VulDB Data Team • 12/19/2024
The vulnerability identified as CVE-2015-7944 affects the RESTful control interface of Ganeti hypervisor management software, specifically targeting versions prior to the mentioned security patches. This issue manifests in the RAPI component when operating in SSL mode, creating a significant security risk that impacts cloud infrastructure deployments relying on Ganeti for virtual machine management. The vulnerability stems from improper handling of SSL parameter renegotiation, which creates a resource exhaustion condition that can be exploited by remote attackers to disrupt service availability.
The technical flaw resides in the SSL implementation within the RAPI module where the system fails to properly validate or limit SSL renegotiation requests. When SSL renegotiation is initiated by an attacker, the system continues to process these requests without adequate resource constraints, leading to exponential resource consumption. This behavior creates a denial of service condition where legitimate requests cannot be processed due to the exhaustion of system resources such as memory and CPU cycles. The vulnerability is particularly dangerous because SSL renegotiation is a legitimate feature that should be supported, but the implementation lacks proper safeguards against abuse.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the entire virtualization infrastructure managed by Ganeti. Organizations relying on cloud computing platforms built on Ganeti may experience complete service outages, affecting multiple virtual machines and potentially disrupting business-critical applications. The resource exhaustion occurs at the protocol level, making it difficult to distinguish between legitimate and malicious requests, which complicates detection and mitigation efforts. This vulnerability particularly affects environments where SSL is mandatory for security compliance, as attackers can exploit the legitimate SSL functionality to create denial of service conditions.
Mitigation strategies for CVE-2015-7944 should prioritize immediate patching of all affected Ganeti versions to the specified secure releases. Organizations should also implement network-level protections such as rate limiting and connection throttling to prevent excessive SSL renegotiation attempts. The implementation of SSL configuration hardening measures including disabling unnecessary SSL renegotiation features and implementing proper resource limits can provide additional defense-in-depth. Security monitoring should be enhanced to detect unusual patterns of SSL renegotiation activity, and incident response procedures should be updated to address this specific denial of service vector.
This vulnerability aligns with CWE-400, which categorizes resource exhaustion issues in software systems, and demonstrates how improper input validation can lead to denial of service conditions. From an ATT&CK perspective, this represents a network denial of service technique that can be used to disrupt availability of critical infrastructure services. The vulnerability also reflects broader concerns about SSL/TLS implementation security where legitimate protocol features can be abused to create security incidents. Organizations should conduct comprehensive vulnerability assessments to identify all instances of affected Ganeti installations and ensure proper configuration management to prevent similar issues in other components of their infrastructure stack.