CVE-2025-27163: Adobe Acrobat Information Disclosure Flaw

CVE-2025-27163 Overview

CVE-2025-27163 is an out-of-bounds read vulnerability affecting Adobe Acrobat Reader that could lead to the disclosure of sensitive memory. This memory corruption flaw allows attackers to read data beyond the intended buffer boundaries, potentially exposing sensitive information stored in memory. Exploitation of this vulnerability requires user interaction—specifically, a victim must open a malicious PDF file crafted by the attacker.

Critical Impact

Successful exploitation enables attackers to bypass Address Space Layout Randomization (ASLR) and other memory protection mitigations, potentially facilitating more sophisticated attacks such as code execution when chained with additional vulnerabilities.

Affected Products

• Adobe Acrobat versions 24.001.30225 and earlier (Classic)
• Adobe Acrobat DC (Continuous track)
• Adobe Acrobat Reader versions 20.005.30748 and earlier (Classic)
• Adobe Acrobat Reader DC (Continuous track)
• Adobe Acrobat Reader versions 25.001.20428 and earlier
• Affected on both Microsoft Windows and Apple macOS platforms

Discovery Timeline

• March 11, 2025 - CVE-2025-27163 published to NVD
• April 28, 2025 - Last updated in NVD database

Technical Details for CVE-2025-27163

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), a memory corruption issue that occurs when software reads data past the end or before the beginning of the intended buffer. In the context of Adobe Acrobat Reader, this flaw exists in the PDF parsing functionality, where improper bounds checking allows memory contents beyond allocated buffers to be accessed.

The local attack vector requires user interaction, meaning an attacker must convince a victim to open a specially crafted PDF document. Once opened, the malicious file triggers the out-of-bounds read condition, allowing the attacker to extract sensitive memory contents. This information disclosure can reveal memory addresses and layout information that would otherwise be protected by ASLR.

Root Cause

The vulnerability stems from insufficient bounds validation when processing PDF document elements. When Adobe Acrobat Reader parses certain structures within a malicious PDF file, it fails to properly verify that read operations remain within the allocated buffer boundaries. This allows an attacker-controlled offset or size parameter to cause the application to read memory outside the intended data structure.

Attack Vector

The attack requires local access through user interaction—the victim must open a malicious PDF file delivered via email attachment, download link, or other social engineering methods. Once the victim opens the crafted PDF document:

1. Adobe Acrobat Reader begins parsing the malicious document structure
2. A specially crafted element triggers the vulnerable code path
3. The out-of-bounds read operation accesses memory beyond buffer boundaries
4. Sensitive memory contents are exposed to the attacker
5. Disclosed memory information can be used to defeat ASLR protection

The vulnerability does not directly allow code execution but provides critical information that significantly enhances the success rate of subsequent exploitation attempts when combined with other vulnerabilities. Technical details of the vulnerability mechanism are available in the Talos Intelligence Vulnerability Report.

Detection Methods for CVE-2025-27163

Indicators of Compromise

• Unusual PDF files with malformed or suspicious embedded objects targeting Acrobat Reader
• Adobe Acrobat Reader crash dumps indicating memory access violations
• Suspicious PDF attachments from unknown or untrusted sources
• Anomalous memory read patterns in Acrobat Reader process activity

Detection Strategies

• Monitor for Adobe Acrobat Reader crashes or exceptions that may indicate exploitation attempts
• Implement endpoint detection rules for suspicious PDF document structures
• Deploy email gateway scanning to identify malicious PDF attachments before delivery
• Utilize behavioral analysis to detect abnormal memory access patterns in PDF reader processes

Monitoring Recommendations

• Enable detailed logging for PDF document processing activities
• Monitor for unusual Adobe Acrobat Reader behavior following document opens
• Track incoming PDF files and correlate with known malicious document indicators
• Implement file integrity monitoring for Acrobat Reader binaries and plugins

How to Mitigate CVE-2025-27163

Immediate Actions Required

• Update Adobe Acrobat and Acrobat Reader to the latest patched versions immediately
• Restrict users from opening PDF documents from untrusted or unknown sources
• Enable Protected View mode in Adobe Acrobat Reader for all documents from external sources
• Implement application whitelisting to control PDF reader execution

Patch Information

Adobe has released security updates addressing this vulnerability as documented in Adobe Security Bulletin APSB25-14. Organizations should update to the following minimum versions:

• Adobe Acrobat DC (Continuous): Update to version later than 24.001.30225
• Adobe Acrobat Reader DC (Continuous): Update to version later than 24.001.30225
• Adobe Acrobat (Classic 2020): Update to version later than 20.005.30748
• Adobe Acrobat Reader (Classic 2020): Update to version later than 20.005.30748
• Adobe Acrobat/Reader (2024): Update to version later than 25.001.20428

Workarounds

• Enable Protected View mode: Edit → Preferences → Security (Enhanced) → Enable Protected View for all files
• Disable JavaScript in Acrobat Reader to reduce attack surface for document-based attacks
• Use alternative PDF readers for documents from untrusted sources until patches are applied
• Implement network-level filtering to block suspicious PDF attachments at email gateways

# Windows Registry configuration to enable Protected View
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\TrustManager" /v bEnableProtectedModeForAllFiles /t REG_DWORD /d 1 /f

# Disable JavaScript in Acrobat Reader via Registry
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\JSPrefs" /v bEnableJS /t REG_DWORD /d 0 /f