CVE-2011-2440 in Acrobat
Summary
by MITRE
Use-after-free vulnerability in Adobe Reader and Acrobat 8.x before 8.3.1, 9.x before 9.4.6, and 10.x before 10.1.1 allows attackers to execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 11/20/2021
The CVE-2011-2440 vulnerability represents a critical use-after-free flaw affecting Adobe Reader and Acrobat software across multiple versions including 8.x before 8.3.1, 9.x before 9.4.6, and 10.x before 10.1.1. This vulnerability falls under the CWE-416 category of Use After Free, which occurs when a program continues to reference memory after it has been freed, creating opportunities for attackers to manipulate program execution flow. The vulnerability arises from improper memory management within the PDF processing components of these Adobe applications, specifically during the handling of certain PDF objects that trigger memory deallocation followed by subsequent access attempts.
The technical exploitation of this vulnerability involves crafting malicious PDF documents that contain specially formatted objects designed to trigger the memory management error during document parsing. When Adobe Reader or Acrobat processes these malformed PDF files, the application allocates memory for certain objects, processes them, and then frees the memory. However, the program continues to reference this freed memory location, allowing an attacker to control what data is loaded into the freed memory space and subsequently execute arbitrary code with the privileges of the victim user. This type of vulnerability is particularly dangerous because it can be triggered through simple document opening, making it highly suitable for social engineering attacks via email attachments or web downloads.
The operational impact of CVE-2011-2440 extends beyond simple code execution as it provides attackers with complete system compromise capabilities. The vulnerability can be leveraged to install malware, steal sensitive data, or establish persistent backdoors on compromised systems. According to ATT&CK framework, this vulnerability maps to T1059.007 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as attackers can leverage the arbitrary code execution to escalate privileges and maintain persistence. The vulnerability's widespread impact is demonstrated by its presence in multiple major software versions, affecting a broad user base including enterprise environments where Adobe Reader remains a common document viewer.
Mitigation strategies for CVE-2011-2440 primarily focus on immediate software updates and administrative controls. Adobe released patches for all affected versions, with the 8.3.1, 9.4.6, and 10.1.1 releases specifically addressing this vulnerability. Organizations should implement immediate patch management procedures to update all affected Adobe Reader and Acrobat installations. Additional protective measures include implementing sandboxing technologies, restricting user privileges when opening PDF documents, and deploying content filtering solutions to block suspicious PDF attachments. Network-based defenses can utilize signature-based detection systems to identify and block known malicious PDF files, while endpoint protection solutions should be configured to monitor for anomalous behavior patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the importance of maintaining current software versions and implementing defense-in-depth strategies to protect against memory corruption vulnerabilities that can lead to complete system compromise.