CVE-2023-26418 in Acrobat Reader
Summary
by MITRE • 04/13/2023
Adobe Acrobat Reader versions 23.001.20093 (and earlier) and 20.005.30441 (and earlier) are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
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Analysis
by VulDB Data Team • 11/09/2025
The vulnerability identified as CVE-2023-26418 represents a critical use after free flaw in Adobe Acrobat Reader software that poses significant security risks to end users. This issue affects specific versions of Adobe Acrobat Reader including those up to and including 23.001.20093 and 20.005.30441, making a substantial portion of the user base potentially vulnerable. The nature of this vulnerability allows for arbitrary code execution when a user opens a maliciously crafted file, effectively providing attackers with a powerful attack vector that leverages user interaction as a prerequisite for exploitation.
The technical root cause of this vulnerability stems from improper memory management within the Adobe Acrobat Reader application where freed memory blocks are still being accessed after they have been deallocated. This use after free condition occurs when the application attempts to reference memory that has already been released back to the system, creating a scenario where malicious code can manipulate the freed memory location to execute unintended operations. The vulnerability falls under the CWE-416 category of use after free conditions, which is a well-documented class of memory safety issues that frequently leads to privilege escalation and arbitrary code execution attacks. From an operational perspective, this vulnerability represents a severe risk because it requires only user interaction to trigger, meaning that simply opening a malicious PDF file can compromise the system. The attack vector is particularly dangerous because it exploits the trust users place in document viewing applications, making it difficult to defend against through traditional network-based security measures.
The impact of successful exploitation extends beyond simple code execution, as it can potentially allow attackers to gain full control over the affected system. This arbitrary code execution capability enables threat actors to install malware, steal sensitive data, modify system configurations, or establish persistent backdoors. The vulnerability's requirement for user interaction makes it particularly challenging to defend against through automated network security solutions alone, as it relies on social engineering aspects that can bypass traditional security controls. Organizations using Adobe Acrobat Reader should be particularly concerned about this vulnerability as it affects a widely deployed application that users frequently interact with, making it an attractive target for cybercriminals. The attack surface is further expanded by the fact that PDF files can be delivered through various channels including email attachments, web downloads, and malicious websites, providing multiple opportunities for exploitation.
Mitigation strategies for CVE-2023-26418 should prioritize immediate patching of affected Adobe Acrobat Reader installations to address the underlying memory management flaw. Security teams should implement comprehensive patch management processes to ensure all vulnerable versions are updated promptly. Additionally, organizations should consider implementing additional security controls such as email filtering solutions that can detect and block potentially malicious PDF files, application whitelisting to restrict execution of unauthorized applications, and user education programs to raise awareness about the risks of opening suspicious documents. Network-based security solutions should be configured to monitor for suspicious PDF file transfers and potentially malicious file downloads. The vulnerability also highlights the importance of maintaining up-to-date software inventory records and implementing automated vulnerability scanning to identify systems running vulnerable versions of Adobe Acrobat Reader. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving social engineering and execution through legitimate user interfaces, making it a critical component of comprehensive security defense strategies that must account for both technical and human factors in the attack chain.