CVE-2025-21157 is an out-of-bounds write vulnerability (CWE-787) found in Adobe InDesign Desktop versions 20.0, 19.5.1, and earlier. This vulnerability arises when the software improperly handles memory bounds during file processing, allowing an attacker to write data outside the intended buffer. Such memory corruption can lead to arbitrary code execution within the context of the current user. The attack vector requires the victim to open a malicious InDesign file, making user interaction mandatory. No authentication is required, and the attack complexity is low, meaning an attacker with a crafted file can exploit the vulnerability without needing additional privileges or complex conditions. The vulnerability affects confidentiality, integrity, and availability, as arbitrary code execution can lead to data theft, system manipulation, or denial of service. Adobe has not yet released patches at the time of this report, and no known exploits have been observed in the wild. The CVSS v3.1 base score is 7.8, indicating high severity, with metrics AV:L (local), AC:L (low complexity), PR:N (no privileges), UI:R (user interaction required), S:U (unchanged scope), and high impact on confidentiality, integrity, and availability. This vulnerability is particularly concerning for organizations relying heavily on Adobe InDesign for desktop publishing and creative workflows, as successful exploitation could compromise sensitive design files and internal systems.

The impact of CVE-2025-21157 is significant for organizations using Adobe InDesign Desktop, especially in creative industries such as publishing, advertising, and media production. Successful exploitation allows attackers to execute arbitrary code with the same privileges as the user, potentially leading to data theft, unauthorized system access, or disruption of services. Since the vulnerability requires opening a malicious file, phishing or social engineering campaigns could be used to deliver the exploit. Compromise could extend to intellectual property loss, exposure of confidential client information, and disruption of critical design workflows. The vulnerability affects confidentiality, integrity, and availability, making it a comprehensive threat. Organizations with lax endpoint security or insufficient user training are at higher risk. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once patches are released or if the vulnerability becomes publicly known.

1. Monitor Adobe’s official channels for security updates and apply patches immediately once released to remediate the vulnerability. 2. Until patches are available, implement strict file handling policies to restrict opening InDesign files from untrusted or unknown sources. 3. Employ endpoint protection solutions capable of detecting and blocking malicious file behavior or anomalous memory operations. 4. Educate users about the risks of opening unsolicited or suspicious files, emphasizing caution with email attachments and downloads. 5. Use application whitelisting to limit execution of unauthorized software and scripts. 6. Consider sandboxing or isolating Adobe InDesign processes to reduce the impact of potential exploitation. 7. Regularly back up critical design files and system configurations to enable recovery in case of compromise. 8. Monitor network and endpoint logs for unusual activity indicative of exploitation attempts. These measures collectively reduce the attack surface and limit the potential damage from exploitation.