CVE-2019-7766 in Acrobat Reader
Summary
by MITRE
Adobe Acrobat and Reader versions 2019.010.20100 and earlier, 2019.010.20099 and earlier, 2017.011.30140 and earlier, 2017.011.30138 and earlier, 2015.006.30495 and earlier, and 2015.006.30493 and earlier have a use after free vulnerability. Successful exploitation could lead to arbitrary code execution.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/17/2024
Adobe Acrobat and Reader applications contain a critical use after free vulnerability that affects multiple versions across different release cycles. This vulnerability stems from improper memory management within the software's handling of PDF objects, specifically when processing certain maliciously crafted PDF files. The flaw occurs when the application frees memory associated with a PDF object but continues to reference that memory location, creating a scenario where subsequent operations can overwrite the freed memory with attacker-controlled data. This memory corruption pattern represents a classic use after free vulnerability that falls under CWE-416, which specifically addresses the use of freed memory in software applications.
The technical exploitation of this vulnerability requires an attacker to craft a malicious PDF file that triggers the specific memory management error during document processing. When a user opens such a crafted document, the application's PDF parser encounters a condition where it frees a memory block containing object references but later attempts to access that same memory location. This creates a race condition where the freed memory can be manipulated by an attacker to redirect execution flow, potentially leading to arbitrary code execution. The vulnerability's impact is particularly severe because it operates at the application level, allowing attackers to execute malicious code with the privileges of the victim user. This aligns with ATT&CK technique T1203, which involves legitimate user privileges being used to execute malicious code through application-level vulnerabilities.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a potential foothold for more sophisticated attacks within the victim's environment. Attackers can leverage this vulnerability to establish persistent access, escalate privileges, or deploy additional malicious payloads. The widespread adoption of Adobe Acrobat and Reader across enterprise environments makes this vulnerability particularly dangerous, as a single compromised system could serve as a vector for broader network infiltration. Organizations running affected versions face significant risk of data breaches, as the vulnerability can be exploited through various attack vectors including email attachments, web downloads, or malicious websites. The vulnerability's exploitation requires minimal user interaction, making it particularly effective in social engineering campaigns where users might inadvertently open malicious documents.
Mitigation strategies for this vulnerability should include immediate patching of all affected Adobe Acrobat and Reader installations to the latest versions that contain memory management fixes. System administrators should implement strict document handling policies, including PDF file scanning and sandboxing mechanisms, to prevent automatic execution of potentially malicious documents. Network segmentation and endpoint protection solutions should be configured to monitor for suspicious PDF file handling activities. Additionally, user education programs should emphasize the importance of only opening PDF files from trusted sources and avoiding unexpected document attachments. Organizations should also consider implementing application whitelisting policies that restrict execution of Adobe Reader in potentially risky contexts, particularly in high-security environments. The vulnerability highlights the critical importance of maintaining up-to-date software patches and implementing defense-in-depth strategies to protect against zero-day exploits that target memory corruption vulnerabilities in widely used applications.