CVE-2012-4063 in Eucalyptus
Summary
by MITRE
The Apache Santuario configuration in Eucalyptus before 3.1.1 does not properly restrict applying XML Signature transforms to documents, which allows remote attackers to cause a denial of service via unspecified vectors.
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Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2012-4063 resides within the Apache Santuario XML security library implementation within the Eucalyptus cloud computing platform. This issue affects versions prior to 3.1.1 and represents a critical configuration flaw that undermines the security posture of the system. The vulnerability specifically targets the XML Signature processing capabilities, which are fundamental to ensuring data integrity and authentication in distributed cloud environments. Eucalyptus, as a cloud infrastructure platform, relies heavily on XML-based communication protocols for various administrative and operational functions, making this vulnerability particularly dangerous as it could potentially compromise the entire cloud deployment.
The technical flaw manifests in the improper restriction of XML Signature transforms within the Apache Santuario configuration. XML Signature transforms are cryptographic operations that modify the data being signed, such as canonicalization, XPath filtering, or other processing steps. When these transforms are not properly constrained, malicious actors can exploit the system to apply unauthorized transformations that may cause the signature validation process to consume excessive computational resources or enter infinite processing loops. This misconfiguration allows attackers to craft specially malformed XML signatures that, when processed by the vulnerable Eucalyptus system, trigger resource exhaustion or other processing anomalies that can lead to system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it represents a potential gateway for more sophisticated attacks within cloud environments. Remote attackers who can submit malicious XML signatures to the vulnerable Eucalyptus system can exploit this flaw to consume significant CPU and memory resources, potentially leading to complete system unavailability. The unspecified vectors mentioned in the CVE description suggest that the attack surface may be broader than initially apparent, potentially affecting various components within the cloud infrastructure that rely on XML signature validation. This vulnerability directly violates the principle of least privilege and proper input validation, creating a scenario where untrusted data can cause system-level resource exhaustion and operational disruption.
The security implications of this vulnerability align with CWE-226, which describes weaknesses in the presence of insufficient logging or monitoring, and CWE-400, which addresses issues related to resource exhaustion. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service, and potentially T1566.001 for initial access through malicious XML processing. The vulnerability demonstrates a classic example of how XML security implementations can become attack vectors when proper transform restrictions are not enforced, particularly in cloud environments where XML-based protocols are extensively used for inter-service communication. Organizations using affected versions of Eucalyptus should immediately implement the available patches or updates to address this configuration flaw and prevent potential exploitation that could lead to service disruption or more severe compromise of cloud infrastructure components.
The remediation for this vulnerability requires updating to Eucalyptus version 3.1.1 or later, which includes proper restrictions on XML Signature transforms within the Apache Santuario configuration. Additionally, system administrators should implement monitoring for unusual XML processing patterns and resource consumption spikes that could indicate exploitation attempts. The fix addresses the core configuration issue by ensuring that only authorized transforms are applied during XML signature validation, preventing attackers from crafting malicious signatures that could trigger resource exhaustion conditions. This vulnerability underscores the critical importance of proper XML security configuration in distributed systems and the potential consequences of inadequate input validation in cloud computing environments where resource management and system stability are paramount concerns.