CVE-2025-27163 is a medium-severity out-of-bounds read vulnerability (CWE-125) affecting multiple versions of Adobe Acrobat Reader, including 24.001.30225, 20.005.30748, and 25.001.20428 and earlier. The vulnerability arises when Acrobat Reader improperly handles certain crafted PDF files, allowing an attacker to read memory beyond the intended buffer boundaries. This memory disclosure can reveal sensitive information that may aid attackers in bypassing Address Space Layout Randomization (ASLR), a key mitigation technique designed to prevent exploitation of memory corruption bugs. Exploitation requires user interaction, as the victim must open a maliciously crafted PDF file. The vulnerability impacts confidentiality by exposing sensitive memory contents but does not directly affect system integrity or availability. The CVSS v3.1 score is 5.5, reflecting a medium risk due to the need for user interaction and local attack vector (local meaning user-level, not remote network). There are no known public exploits in the wild at this time, but the vulnerability's nature means it could be leveraged in targeted attacks or combined with other vulnerabilities for privilege escalation or code execution. Adobe has not yet provided patches, so users must remain vigilant. The flaw is categorized under CWE-125, which is a common class of memory safety errors leading to out-of-bounds reads.

The primary impact of CVE-2025-27163 is the potential disclosure of sensitive information from the memory space of Adobe Acrobat Reader processes. This can lead to attackers gaining insights into memory layout and security mitigations like ASLR, which could facilitate further exploitation such as code execution or privilege escalation in multi-stage attacks. While the vulnerability itself does not allow direct code execution or system compromise, it weakens the overall security posture of affected systems. Organizations handling sensitive documents or operating in high-security environments could face increased risk of data leakage or targeted attacks. Since exploitation requires user interaction, social engineering or phishing campaigns distributing malicious PDFs are likely attack vectors. The vulnerability affects a widely used PDF reader, so the scope is broad, potentially impacting enterprises, government agencies, and individual users globally. The absence of known exploits currently reduces immediate risk but does not eliminate the threat of future exploitation.

1. Monitor Adobe security advisories closely and apply official patches immediately once released to remediate the vulnerability. 2. Until patches are available, implement strict email filtering and endpoint protection to block or quarantine suspicious PDF attachments. 3. Educate users about the risks of opening unsolicited or unexpected PDF files, emphasizing caution with email attachments from unknown or untrusted sources. 4. Use sandboxing or application isolation techniques to open PDF files in restricted environments, limiting potential memory disclosure impact. 5. Employ network-level protections such as Data Loss Prevention (DLP) to detect and prevent sensitive data exfiltration. 6. Consider disabling JavaScript and other potentially exploitable features within Acrobat Reader to reduce attack surface. 7. Maintain up-to-date antivirus and endpoint detection and response (EDR) solutions capable of detecting malicious PDF behaviors. 8. Review and tighten access controls on sensitive documents to minimize exposure if a memory disclosure occurs.