CVE-2011-0591 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 crafted Universal 3D (U3D) file that triggers a buffer overflow during decompression, related to Texture and rgba, a different vulnerability than CVE-2011-0590, CVE-2011-0592, CVE-2011-0593, CVE-2011-0595, and CVE-2011-0600.
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Analysis
by VulDB Data Team • 10/16/2021
Adobe Reader and Acrobat versions prior to 10.0.1, 9.4.2, and 8.2.6 contain a critical buffer overflow vulnerability in their Universal 3D (U3D) file decompression engine. This vulnerability specifically affects the handling of Texture and rgba data structures within U3D files, creating a remote code execution vector that can be exploited by attackers who craft malicious U3D files. The flaw resides in the decompression logic that processes these specific data elements, where insufficient bounds checking allows an attacker to overflow memory buffers and potentially overwrite critical program execution data. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when data is written beyond the allocated buffer boundaries during the decompression of U3D file components. This issue represents a distinct vulnerability from other related CVEs in the same year, specifically separate from CVE-2011-0590 through CVE-2011-0600, indicating a unique code path and memory handling pattern within the U3D parsing implementation. The attack vector requires a remote delivery mechanism where a victim must open a specially crafted U3D file, typically through email attachments, web downloads, or malicious websites that host the malicious content. When the vulnerable application processes the malicious file, the buffer overflow can result in arbitrary code execution with the privileges of the user running the application, potentially allowing full system compromise. This vulnerability aligns with ATT&CK technique T1203 by enabling remote code execution through application exploitation, and T1068 which covers privilege escalation opportunities. The impact is particularly severe given that Adobe Reader and Acrobat are widely deployed across enterprise environments, making this vulnerability attractive to threat actors seeking persistent access to target networks. The vulnerability affects both Windows and Mac OS X platforms, indicating a cross-platform implementation issue in the U3D parsing code. The buffer overflow occurs during the decompression phase of U3D file processing, specifically when handling texture data and rgba color information, suggesting that the vulnerability is triggered by malformed data within these particular file structures. Organizations running affected versions of Adobe Reader and Acrobat should immediately apply patches from Adobe's security bulletin, as the vulnerability can be exploited without user interaction once the malicious file is opened. The memory corruption pattern typical of buffer overflows makes this vulnerability particularly dangerous as it can be leveraged for privilege escalation attacks, potentially allowing attackers to gain system-level privileges through the exploitation of this memory corruption vulnerability. This vulnerability demonstrates the ongoing challenges in securing complex multimedia file parsing engines and highlights the importance of robust input validation and memory safety practices in software development.
The technical implementation of the vulnerability stems from inadequate input validation within Adobe's U3D decompression library, where the application fails to properly validate the size and structure of Texture and rgba data elements before attempting to decompress them into memory buffers. This failure creates a predictable exploitation pattern where attackers can craft U3D files with oversized or malformed data structures that exceed the bounds of allocated memory regions. The vulnerability specifically impacts the application's handling of color and texture data within 3D models, where the rgba data format is processed without sufficient boundary checks, leading to memory corruption that can be leveraged for code execution. The buffer overflow occurs during the parsing phase when the decompression engine attempts to process color information and texture mapping data, which are standard components of 3D graphics files but become exploitable when malformed. This vulnerability type is particularly concerning because it can be triggered through legitimate application functionality, making it difficult to detect through traditional network monitoring or endpoint protection mechanisms. The exploitation requires careful crafting of the U3D file structure to ensure that the overflow occurs at a specific memory location that allows for control flow hijacking, typically through stack pointer manipulation or return address overwriting. The vulnerability's presence in multiple major versions of Adobe's software indicates a fundamental flaw in the codebase that affects a broad user base, emphasizing the need for comprehensive patch management across enterprise environments. Security researchers have noted that the vulnerability's exploitation is relatively straightforward for skilled attackers, as it does not require advanced exploitation techniques beyond crafting the specific buffer overflow payload. The vulnerability's classification as a remote code execution flaw makes it particularly dangerous in enterprise environments where users may inadvertently open malicious attachments or visit compromised websites, leading to potential full system compromise.
Mitigation strategies for this vulnerability should prioritize immediate patch deployment as the primary defense mechanism, with organizations monitoring Adobe's security advisories for updated versions. The vulnerability's nature as a buffer overflow makes it susceptible to exploitation techniques such as stack pivoting or return-oriented programming attacks, which can be mitigated through modern exploit protection mechanisms including address space layout randomization, stack canaries, and data execution prevention. Organizations should implement application whitelisting policies to restrict execution of Adobe Reader and Acrobat only from trusted sources, and consider deploying sandboxing technologies to isolate the application execution environment. Network-based protections should include filtering of U3D file types at perimeter defenses, particularly in email gateways and web proxies, to prevent automatic delivery of potentially malicious content. The vulnerability's cross-platform nature requires consistent patch management across both Windows and Mac OS X environments, with particular attention to enterprise deployment scenarios where multiple versions may coexist. Security teams should monitor for indicators of compromise related to this vulnerability, including unusual network connections, process execution patterns, or file access activities that might indicate exploitation attempts. The vulnerability's impact on enterprise security infrastructure underscores the importance of maintaining current software versions and implementing robust vulnerability management processes. Regular security assessments should include verification of Adobe Reader and Acrobat installations to ensure all systems are running patched versions, particularly in environments where legacy systems may be running older versions that are no longer supported. The vulnerability's exploitation potential makes it a high priority for security teams to address through comprehensive remediation strategies that include both immediate patching and long-term security hardening measures. Organizations should also consider implementing user education programs to raise awareness about the risks of opening untrusted file attachments and visiting suspicious websites that may host malicious U3D files. The vulnerability's presence in widely used software applications demonstrates the critical importance of maintaining up-to-date security patches and implementing layered defense strategies to protect against remote code execution vulnerabilities.