CVE-2012-3363 in Zend
Summary
by MITRE
Zend_XmlRpc in Zend Framework 1.x before 1.11.12 and 1.12.x before 1.12.0 does not properly handle SimpleXMLElement classes, which allows remote attackers to read arbitrary files or create TCP connections via an external entity reference in a DOCTYPE element in an XML-RPC request, aka an XML external entity (XXE) injection attack.
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Analysis
by VulDB Data Team • 01/17/2025
The vulnerability identified as CVE-2012-3363 represents a critical XML external entity injection flaw within the Zend Framework's XML-RPC implementation. This issue affects versions prior to 1.11.12 and 1.12.0, exposing applications that rely on Zend Framework's XML-RPC functionality to significant security risks. The flaw stems from insufficient validation of XML documents when processing SimpleXMLElement classes, creating an avenue for malicious actors to exploit the system through carefully crafted XML-RPC requests.
The technical exploitation occurs through the manipulation of DOCTYPE elements within XML-RPC requests, specifically targeting external entity references that trigger unintended file system access or network connections. When the vulnerable Zend Framework components process these requests, they fail to properly sanitize or restrict external entity declarations, allowing attackers to reference external resources that could contain sensitive data or enable unauthorized network communication. This vulnerability directly maps to CWE-611, which classifies improper restriction of XML external entity reference as a critical weakness in web applications.
The operational impact of this vulnerability extends beyond simple data exposure, as it enables attackers to perform reconnaissance activities by reading arbitrary files from the server's file system. Additionally, the ability to create TCP connections through external entity references opens pathways for attackers to establish network tunnels or communicate with external systems, potentially leading to further exploitation or data exfiltration. This type of attack aligns with ATT&CK technique T1566.001, which describes the use of malicious XML external entity references in initial access and reconnaissance phases of cyber operations.
Organizations utilizing affected versions of Zend Framework must implement immediate mitigations to address this vulnerability. The primary solution involves upgrading to patched versions of the framework, specifically versions 1.11.12 or 1.12.0 and later. Additionally, developers should implement strict XML parsing configurations that disable external entity resolution and DTD processing when handling XML-RPC requests. Network-level controls such as firewalls and intrusion detection systems can provide additional defense-in-depth measures, though these should not replace proper application-level fixes. Security teams should also conduct comprehensive vulnerability assessments to identify all applications using affected framework versions and ensure proper patching across the entire infrastructure.