CVE-2025-43578 is an out-of-bounds read vulnerability (CWE-125) affecting multiple versions of Adobe Acrobat Reader, including versions 24.001.30235, 20.005.30763, 25.001.20521, and earlier. This vulnerability allows an attacker to read memory outside the intended bounds, potentially leading to the disclosure of sensitive information stored in memory. The flaw can be exploited by convincing a user to open a specially crafted malicious PDF file, which triggers the out-of-bounds read condition. One significant consequence of this vulnerability is that it can be leveraged to bypass security mitigations such as Address Space Layout Randomization (ASLR), which is designed to prevent attackers from reliably executing code by randomizing memory addresses. Although the vulnerability does not directly allow code execution or system compromise, the ability to disclose sensitive memory contents can facilitate further attacks or information leakage. The CVSS v3.1 base score is 5.5, reflecting a medium severity level. The attack vector is local (AV:L), requiring user interaction (UI:R) but no privileges (PR:N). The vulnerability impacts confidentiality (C:H) but not integrity or availability. No known exploits are currently reported in the wild, and no patches or fixes have been linked yet, indicating that organizations should be vigilant and monitor for updates from Adobe.

For European organizations, the impact of CVE-2025-43578 centers primarily on confidentiality breaches. Sensitive information such as cryptographic keys, personal data, or internal application states could be exposed if an attacker successfully exploits this vulnerability. This could lead to data leaks, compliance violations (e.g., GDPR), and potential reputational damage. Since Adobe Acrobat Reader is widely used across enterprises, government agencies, and critical infrastructure sectors in Europe, the risk is non-trivial. The requirement for user interaction means that phishing or social engineering campaigns could be used to deliver malicious PDFs, increasing the attack surface. While the vulnerability does not directly compromise system integrity or availability, the ability to bypass ASLR could facilitate more advanced exploits if chained with other vulnerabilities. Therefore, organizations handling sensitive or regulated data should prioritize mitigation to prevent information disclosure and potential escalation.

1. Implement strict email and document filtering to block or quarantine suspicious PDF files, especially those from unknown or untrusted sources. 2. Educate users about the risks of opening unsolicited or unexpected PDF attachments and encourage verification before opening. 3. Deploy endpoint detection and response (EDR) solutions capable of detecting anomalous behavior related to PDF processing. 4. Monitor Adobe's security advisories closely and apply patches or updates promptly once available. 5. Consider using sandboxing or isolated environments for opening PDF files from external sources to contain potential exploitation. 6. Employ Data Loss Prevention (DLP) tools to monitor and prevent unauthorized exfiltration of sensitive information that could result from exploitation. 7. Restrict the use of outdated Acrobat Reader versions and enforce updates to the latest secure versions as soon as patches are released.