CVE-2022-27787 in Acrobat Reader
Summary
by MITRE • 05/11/2022
Acrobat Reader DC versions 22.001.20085 (and earlier), 20.005.3031x (and earlier) and 17.012.30205 (and earlier) are affected by an out-of-bounds write 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 • 05/14/2022
This vulnerability represents a critical out-of-bounds write flaw in Adobe Acrobat Reader DC across multiple version lines including 22.001.20085 and earlier, 20.005.3031x and earlier, and 17.012.30205 and earlier. The flaw occurs during the processing of specially crafted PDF files and allows an attacker to execute arbitrary code with the privileges of the currently logged-in user. This vulnerability falls under the CWE-787 out-of-bounds write classification, which is a fundamental memory safety issue that can lead to complete system compromise when exploited successfully. The vulnerability requires user interaction for exploitation, meaning a victim must voluntarily open a maliciously crafted PDF file to trigger the exploit, making it a typical target for social engineering attacks.
The technical implementation of this vulnerability involves improper bounds checking during PDF parsing operations within the Acrobat Reader application. When processing malformed PDF content, the application fails to validate array indices or buffer limits before writing data, allowing an attacker to write beyond allocated memory boundaries. This memory corruption can overwrite critical program structures, function pointers, or return addresses, enabling attackers to redirect execution flow and inject malicious code. The attack vector is specifically designed around PDF file manipulation, leveraging the widespread use of Adobe Reader for document viewing across enterprise and personal environments. According to ATT&CK framework, this represents a technique categorized under T1203 Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute code on target systems.
The operational impact of this vulnerability extends beyond simple code execution, as successful exploitation can lead to complete system compromise and persistent access. Attackers can leverage this vulnerability to establish backdoors, escalate privileges, or deploy additional malware payloads. The fact that this affects multiple version lines means a substantial portion of users remain vulnerable, particularly in enterprise environments where legacy software adoption is common. Organizations running older versions of Acrobat Reader DC are at heightened risk since these versions have been released for several years and may not receive timely updates. The vulnerability's requirement for user interaction creates a significant attack surface through phishing campaigns, malicious email attachments, or compromised websites serving malicious PDF content. Security professionals should consider this vulnerability as part of their threat modeling exercises, particularly in environments where PDF document handling is common.
Mitigation strategies should focus on immediate software updates to the latest versions of Adobe Acrobat Reader DC where this vulnerability has been patched. Organizations should implement strict document handling policies, including PDF file scanning and sandboxing for untrusted documents. Network-level controls such as web application firewalls and content filtering systems can help prevent access to known malicious PDF sources. Additionally, user education programs should emphasize the importance of verifying document sources and avoiding opening suspicious attachments. Security monitoring should include detection of unusual PDF processing activities and potential exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date software and implementing defense-in-depth strategies to protect against zero-day exploits targeting widely used applications. System administrators should prioritize patch management processes to ensure all Acrobat Reader installations are updated promptly.