CVE-2017-11238 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat Reader 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier has an exploitable memory corruption vulnerability in the image conversion engine when processing Enhanced Metafile Format (EMF) data related to curve drawing. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/30/2024
This vulnerability exists within Adobe Acrobat Reader's image conversion engine which processes Enhanced Metafile Format (EMF) data structures. The flaw manifests when handling curve drawing operations within EMF files, specifically during the conversion process from EMF to other image formats. The memory corruption occurs due to improper bounds checking and memory management within the rendering pipeline that processes vector graphics data. This vulnerability affects multiple versions of Adobe Acrobat Reader including 2017.009.20058 and earlier, 2017.008.30051 and earlier, 2015.006.30306 and earlier, and 11.0.20 and earlier versions, indicating a persistent issue in the software's graphics processing subsystem that spans several major releases.
The technical exploitation of this vulnerability involves crafting a malicious EMF file that contains malformed curve drawing commands which trigger buffer overflows or memory corruption when processed by the affected Adobe Reader versions. When a user opens such a specially crafted file, the image conversion engine attempts to render the EMF content, leading to memory corruption that can be leveraged by attackers to execute arbitrary code with the privileges of the victim user. This type of vulnerability falls under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are common in graphics processing libraries where buffer management is critical. The attack vector is typically through social engineering where users are tricked into opening malicious attachments or visiting compromised websites that deliver the malicious EMF content.
The operational impact of this vulnerability is significant as it allows remote code execution without requiring user interaction beyond opening a malicious document, making it particularly dangerous in enterprise environments where users frequently open PDF documents from various sources. Attackers can leverage this vulnerability to establish persistent access, escalate privileges, or deploy additional malware payloads. The vulnerability aligns with ATT&CK technique T1059.007 which describes scripting through command-line interfaces, as the executed code can leverage system resources and potentially establish reverse shells or command-and-control communications. Organizations using older versions of Adobe Acrobat Reader face substantial risk as these versions lack the memory safety mechanisms and input validation that would prevent such exploitation scenarios.
Mitigation strategies should prioritize immediate patching of all affected Adobe Acrobat Reader installations to the latest versions that contain memory safety fixes and improved bounds checking. System administrators should implement strict document filtering policies that prevent execution of potentially malicious EMF content, particularly in high-risk environments. Network segmentation and application whitelisting can help limit the attack surface by restricting which systems can process PDF documents. Additionally, user education programs should emphasize the importance of only opening documents from trusted sources and maintaining current software versions. Security monitoring should focus on detecting unusual file processing activities and potential exploitation attempts through network traffic analysis and endpoint detection systems. The vulnerability demonstrates the critical importance of regular software updates and maintaining current security patches as a fundamental defense against known exploitation techniques.