CVE-2025-43591 is a heap-based buffer overflow vulnerability identified in Adobe InDesign Desktop versions 19.5.3 and earlier. This vulnerability arises from improper handling of memory buffers on the heap, which can be exploited when a user opens a specially crafted malicious file. The flaw allows an attacker to overwrite memory beyond the allocated buffer, potentially leading to arbitrary code execution within the security context of the current user. Exploitation requires user interaction, specifically opening a malicious InDesign file, making social engineering or phishing a likely attack vector. The vulnerability is classified under CWE-122, indicating a heap-based buffer overflow. The CVSS v3.1 score is 7.8, reflecting high severity with a vector string of AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, meaning the attack requires local access (local vector), low attack complexity, no privileges required, user interaction required, unchanged scope, and high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild yet, and no patches have been linked at the time of this report. The vulnerability poses a significant risk to users of Adobe InDesign Desktop, particularly those who handle untrusted or externally sourced InDesign files, as successful exploitation could lead to full compromise of the affected user's environment within the application context.

For European organizations, this vulnerability presents a considerable risk, especially for industries heavily reliant on Adobe InDesign for desktop publishing, such as media, advertising, publishing, and design firms. Successful exploitation could lead to arbitrary code execution, enabling attackers to steal sensitive information, disrupt workflows, or establish persistence within compromised systems. Given the high confidentiality, integrity, and availability impacts, attackers could exfiltrate intellectual property or deploy ransomware or other malware. The requirement for user interaction limits mass exploitation but does not eliminate targeted attacks, particularly spear-phishing campaigns aimed at creative professionals. The local attack vector suggests that attackers may need initial access or social engineering to deliver the malicious file. European organizations with remote or hybrid work environments may face increased risk if users open malicious files on less secure endpoints. Additionally, the lack of a patch at the time of disclosure increases the window of exposure, necessitating immediate mitigation efforts.

1. Immediate user awareness training focused on the risks of opening unsolicited or unexpected InDesign files, emphasizing verification of file sources before opening. 2. Implement strict email filtering and attachment scanning to detect and quarantine potentially malicious InDesign files. 3. Employ application whitelisting and sandboxing techniques for Adobe InDesign to limit the impact of potential exploitation. 4. Restrict local user permissions to the minimum necessary to reduce the impact of arbitrary code execution. 5. Monitor for unusual application behavior or crashes related to InDesign, which may indicate exploitation attempts. 6. Maintain up-to-date backups of critical data to enable recovery in case of compromise. 7. Coordinate with Adobe for timely patch deployment once available, and consider temporary disabling of InDesign usage in high-risk environments until patches are released. 8. Use endpoint detection and response (EDR) tools to identify and respond to suspicious activities related to InDesign processes.