CVE-2025-21134 is an integer underflow vulnerability (CWE-191) identified in Adobe Illustrator on iPad, specifically versions 3.0.7 and earlier. Integer underflow occurs when an arithmetic operation causes a value to wrap around below its minimum representable value, potentially leading to memory corruption. In this case, the vulnerability can be triggered by opening a maliciously crafted file, which causes the application to mishandle internal data structures or buffer sizes. This improper handling can lead to arbitrary code execution within the context of the current user, allowing an attacker to execute malicious payloads, manipulate files, or disrupt application behavior. The vulnerability requires user interaction (opening a file), no privileges are needed beforehand, and the attack surface is limited to users who open untrusted Illustrator files on iPad devices. The CVSS 3.1 base score of 7.8 reflects high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Currently, there are no publicly known exploits in the wild, but the vulnerability poses a significant risk to users of affected versions. Adobe has not yet released a patch, so mitigation relies on cautious file handling and user awareness.

The exploitation of CVE-2025-21134 could have severe consequences for organizations and individuals using Adobe Illustrator on iPad. Successful attacks could lead to arbitrary code execution, enabling attackers to steal sensitive design files, intellectual property, or credentials stored or accessed via the device. The integrity of creative work could be compromised, and availability of the application or device could be disrupted through crashes or persistent malware. Since the vulnerability executes code with user-level privileges, attackers could potentially escalate privileges through chained exploits. Industries relying heavily on digital design, such as advertising, media, and product design, face increased risk of espionage or sabotage. The requirement for user interaction limits mass exploitation but does not prevent targeted spear-phishing or supply chain attacks involving malicious Illustrator files. The lack of a patch increases exposure duration, emphasizing the need for interim protective measures.

To mitigate CVE-2025-21134, organizations should implement the following specific measures: 1) Educate users to avoid opening Illustrator files from untrusted or unknown sources, especially on iPad devices. 2) Employ mobile device management (MDM) solutions to restrict installation of unapproved applications and control file sharing policies. 3) Use network-level protections such as email and web filtering to block or quarantine suspicious files before reaching end users. 4) Monitor for unusual application behavior or crashes that could indicate exploitation attempts. 5) Regularly back up critical design files to secure, isolated storage to prevent data loss. 6) Coordinate with Adobe for timely updates and apply patches immediately upon release. 7) Consider disabling or limiting Illustrator file preview features in email clients or file browsers on iPad to reduce attack surface. 8) Implement endpoint detection and response (EDR) tools capable of identifying anomalous code execution patterns on iPad devices if supported. These targeted steps go beyond generic advice by focusing on user behavior, device management, and proactive detection tailored to the iPad environment and Illustrator usage.