CVE-2022-34220 in Acrobat Reader
Summary
by MITRE • 07/15/2022
Adobe Acrobat Reader versions 22.001.20142 (and earlier), 20.005.30334 (and earlier) and 17.012.30229 (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 • 07/15/2022
Adobe Acrobat Reader contains a use after free vulnerability in its handling of PDF documents that allows remote attackers to execute arbitrary code on affected systems. This vulnerability exists due to improper memory management when processing specially crafted PDF files that contain malicious objects. The flaw occurs when the application attempts to free memory associated with a PDF object and subsequently accesses that same memory location without proper validation, creating a condition where an attacker can manipulate the freed memory to execute malicious code. The vulnerability is classified as a use after free error under CWE-416, which represents a critical memory safety issue that can lead to arbitrary code execution. The attack requires user interaction through social engineering to convince victims to open a malicious PDF file, making it a client-side exploitation vector that targets end users rather than network infrastructure. The affected versions include Adobe Acrobat Reader 22.001.20142 and earlier, 20.005.30334 and earlier, and 17.012.30229 and earlier, indicating this vulnerability has been present across multiple major release lines. The security impact of this vulnerability aligns with ATT&CK technique T1203, which involves gaining access to systems through malicious documents, and T1059, which covers execution through various payloads. When successfully exploited, the vulnerability allows an attacker to execute arbitrary code with the privileges of the current user, potentially leading to full system compromise. The memory corruption aspect of this vulnerability makes it particularly dangerous as it can be leveraged to overwrite critical program structures or inject malicious code into the application's memory space. The vulnerability affects users who open PDF files from untrusted sources, making it especially concerning in enterprise environments where PDF documents are frequently shared and opened by multiple users. The exploitation process typically involves crafting a malicious PDF file that triggers the memory management error during document parsing, followed by the execution of shellcode or other malicious payloads. This type of vulnerability is particularly challenging to defend against because it requires legitimate user interaction and can be easily disguised as legitimate documents. The use after free condition can be exploited through various attack vectors including embedded malicious code, malformed objects, or crafted JavaScript within PDF files that trigger the memory corruption when parsed by the vulnerable application. Organizations should prioritize patching affected versions of Adobe Acrobat Reader to prevent exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date software and implementing proper document handling policies to prevent users from opening potentially malicious files. Security controls should include email filtering to identify suspicious PDF attachments, user education about the risks of opening unknown documents, and regular software updates to address known vulnerabilities. Network-based defenses alone are insufficient since the exploitation requires local user interaction, making endpoint protection and user awareness critical components of defense. The vulnerability also highlights the need for proper input validation and memory management practices in document processing applications, as these types of flaws can provide attackers with direct paths to system compromise. Adobe has addressed this vulnerability through security updates that correct the memory management issues in the affected versions, requiring users to update their installations to receive protection against exploitation attempts.