CVE-2011-0594 in Acrobat Reader
Summary
by MITRE
Adobe Reader and Acrobat 10.x before 10.0.1, 9.x before 9.4.2, and 8.x before 8.2.6 on Windows and Mac OS X allow remote attackers to execute arbitrary code via a font.
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Analysis
by VulDB Data Team • 10/16/2021
Adobe Reader and Acrobat versions prior to specific patches contain a critical buffer overflow vulnerability in their font processing functionality that enables remote code execution attacks. This vulnerability affects multiple product versions including Adobe Reader 10.x before 10.0.1, 9.x before 9.4.2, and 8.x before 8.2.6 across both Windows and Mac OS X operating systems. The flaw exists within the handling of font files when these applications process embedded fonts in PDF documents, creating an exploitable condition that allows attackers to craft malicious PDF files containing specially crafted font data.
The technical nature of this vulnerability stems from insufficient bounds checking during font parsing operations, specifically when Adobe Reader and Acrobat attempt to process font files with malformed or oversized data structures. When a user opens a malicious PDF document containing crafted font data, the application's font processing engine fails to properly validate input boundaries, leading to memory corruption that can be exploited to overwrite critical memory locations. This buffer overflow condition occurs in the font rendering subsystem where the application attempts to copy font data into fixed-size buffers without adequate validation of the source data length. The vulnerability maps to CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness in software design that allows attackers to overwrite adjacent memory locations and potentially execute arbitrary code with the privileges of the affected application.
The operational impact of this vulnerability is severe as it enables remote code execution without requiring user interaction beyond opening a malicious PDF document, making it particularly dangerous in targeted attack scenarios. Attackers can leverage this vulnerability to deliver malware payloads, establish persistent backdoors, or perform privilege escalation attacks on compromised systems. The vulnerability affects a wide range of users since Adobe Reader and Acrobat are widely deployed across enterprise environments and personal computing systems. Once successfully exploited, the attacker gains the ability to execute arbitrary code in the context of the affected application, potentially leading to complete system compromise. This vulnerability is classified under the MITRE ATT&CK framework as part of the Execution tactic, specifically targeting the use of PDF files as attack vectors for code execution.
Organizations should immediately implement the vendor-provided security patches for Adobe Reader and Acrobat versions affected by this vulnerability. The recommended mitigation strategy includes deploying the latest security updates from Adobe, which address the buffer overflow condition through proper input validation and bounds checking in font processing operations. System administrators should also consider implementing additional security controls such as PDF file filtering, sandboxing mechanisms, and network-based intrusion detection systems to monitor for suspicious PDF file activity. Regular security assessments and vulnerability scanning should be conducted to identify systems running unpatched versions of Adobe Reader and Acrobat, as well as to verify that appropriate security measures have been implemented. The vulnerability serves as a reminder of the critical importance of keeping document processing software up to date and implementing defense-in-depth strategies to protect against sophisticated attacks targeting common software applications.