CVE-2024-49535 in Acrobat Reader
Summary
by MITRE • 12/10/2024
Acrobat Reader versions 24.005.20307, 24.001.30213, 24.001.30193, 20.005.30730, 20.005.30710 and earlier are affected by an Improper Restriction of XML External Entity Reference ('XXE') vulnerability that could result in arbitrary code execution. This vulnerability allows an attacker to provide malicious XML input containing a reference to an external entity, leading to data disclosure or potentially code execution. Exploitation of this issue requires user interaction in that a victim must process a malicious XML document.
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Analysis
by VulDB Data Team • 02/19/2025
The vulnerability identified as CVE-2024-49535 represents a critical Improper Restriction of XML External Entity Reference flaw affecting multiple versions of Adobe Acrobat Reader. This weakness falls under the CWE-611 category, specifically targeting XML external entity processing mechanisms that fail to properly validate or restrict external entity references. The vulnerability exists within the document parsing functionality of Acrobat Reader, where the application processes XML content without adequate safeguards against malicious external entity declarations. Attackers can exploit this by crafting specially formatted XML documents that contain references to external resources, potentially leading to unauthorized data access or remote code execution. The flaw is particularly concerning because it requires only user interaction to exploit, meaning victims must simply open or process a malicious XML file to be compromised.
The technical implementation of this vulnerability stems from Acrobat Reader's insufficient XML parsing controls during document processing. When the application encounters XML content within PDF documents or associated files, it fails to properly sanitize external entity references, allowing attackers to define custom entities that can reference external resources. This misconfiguration enables attackers to craft XML payloads that can access local files, perform server-side requests, or execute arbitrary commands depending on the system configuration. The XXE vulnerability operates at the application layer and can be leveraged to bypass traditional network security controls, as the malicious XML processing occurs within the trusted application environment rather than through network-based attacks. The exploitation requires user interaction because the malicious XML content must be processed by the vulnerable application, typically through opening a PDF file containing embedded XML.
The operational impact of CVE-2024-49535 extends beyond simple data disclosure, potentially enabling full system compromise when attackers can leverage the XXE vulnerability for remote code execution. Organizations using affected Acrobat Reader versions face significant risk exposure, particularly in environments where users regularly process PDF documents from untrusted sources. The vulnerability affects multiple product versions, indicating a widespread issue that requires immediate attention across various deployment scenarios. Attackers can utilize this vulnerability to access sensitive files on the local system, potentially exfiltrating confidential data or establishing persistent access through command execution capabilities. The attack surface is broadened by the fact that PDF documents can be distributed through various channels including email attachments, web downloads, and shared network drives, making it difficult to prevent exploitation entirely.
Mitigation strategies for CVE-2024-49535 must prioritize immediate software updates to the latest Acrobat Reader versions that contain patches addressing the XXE vulnerability. Organizations should implement comprehensive application whitelisting policies to restrict execution of potentially malicious XML content and establish strict document handling procedures for untrusted files. Network-based defenses should include XML filtering rules that block external entity references and monitor for suspicious XML content patterns. Security teams should conduct regular vulnerability assessments targeting PDF processing applications and implement user education programs to reduce the risk of social engineering attacks that rely on user interaction. The ATT&CK framework categorizes this vulnerability under T1059 for remote code execution and T1566 for social engineering, emphasizing the need for layered defensive approaches that address both technical controls and human factors in the attack chain. Organizations should also consider implementing sandboxing mechanisms for PDF processing and regularly audit their document handling workflows to identify potential XXE attack vectors.