CVE-2019-7781 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.
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Analysis
by VulDB Data Team • 06/16/2024
Adobe Acrobat and Reader contain a use after free vulnerability in their handling of PDF documents that affects multiple versions across different release cycles. This vulnerability stems from improper memory management where a program continues to reference memory locations after they have been freed, creating a condition that can be exploited by malicious actors. The flaw exists in the parsing and processing mechanisms of PDF files, specifically within the document rendering engine that handles various object types and their associated memory allocations.
The technical implementation of this vulnerability allows attackers to craft malicious PDF files that trigger the use after free condition during normal document processing operations. When the application encounters specially constructed objects within the PDF, it may free memory associated with certain data structures while still maintaining pointers to those locations. This creates a scenario where subsequent operations can write data to the freed memory space, potentially allowing an attacker to overwrite critical function pointers or control structures. The vulnerability is particularly dangerous because it can be triggered through normal user interaction with PDF documents, making it a prime target for social engineering attacks.
Successful exploitation of this vulnerability can result in arbitrary code execution on the target system with the privileges of the user running the vulnerable Adobe application. The attacker can leverage the use after free condition to inject and execute malicious code within the application's memory space, potentially leading to full system compromise. This represents a critical security risk as it enables attackers to bypass standard security controls and gain persistent access to affected systems. The vulnerability affects multiple versions of Adobe Acrobat and Reader, spanning from 2015 through 2019 releases, indicating a long-standing issue that has persisted across several product iterations.
The impact of this vulnerability extends beyond simple code execution, as it can enable attackers to establish persistent backdoors, escalate privileges, or exfiltrate sensitive data from compromised systems. Organizations using these vulnerable versions face significant risk from targeted attacks, particularly in environments where users frequently open PDF documents from untrusted sources. The vulnerability aligns with CWE-416, which describes the use after free condition, and represents a common attack vector that aligns with techniques documented in the ATT&CK framework under process injection and code execution tactics. The widespread adoption of Adobe Reader makes this vulnerability particularly attractive to threat actors seeking to maximize their attack surface.
Organizations should immediately update to the latest versions of Adobe Acrobat and Reader that contain patches for this vulnerability. Adobe has released security updates addressing this issue, and administrators should prioritize deployment of these patches across all affected systems. Additional mitigations include implementing PDF sandboxing features, restricting user privileges when opening PDF documents, and deploying network security controls to filter potentially malicious PDF files. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable software within the organization's environment. The vulnerability demonstrates the importance of maintaining up-to-date software and the critical nature of memory safety in preventing exploitation of such fundamental programming errors.