CVE-2021-21075 in Animate
Summary
by MITRE • 03/13/2021
Adobe Animate version 21.0.3 (and earlier) is affected by an Out-of-bounds Read vulnerability. An unauthenticated attacker could leverage this vulnerability to disclose sensitive information in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
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Analysis
by VulDB Data Team • 05/04/2025
Adobe Animate version 21.0.3 and earlier contains a critical out-of-bounds read vulnerability that falls under CWE-129 Input Validation and OWASP Top Ten category A03: Injection. This vulnerability stems from insufficient bounds checking in the application's handling of malformed file structures, specifically within the parsing logic for animation files. The flaw exists in the software's memory management system where it fails to properly validate array indices before accessing memory locations, creating a condition where arbitrary memory locations can be read without proper authorization. The vulnerability is classified as an out-of-bounds read because the application attempts to access memory beyond the allocated buffer boundaries, potentially exposing sensitive data from adjacent memory regions. This type of vulnerability is particularly dangerous as it can reveal confidential information such as encryption keys, user credentials, or system memory contents that could be leveraged for further exploitation.
The exploitation of this vulnerability requires social engineering through user interaction, making it a client-side attack vector that relies on users opening maliciously crafted animation files. Attackers can create specially designed .swf or .anm files that trigger the out-of-bounds read condition when opened by the vulnerable Adobe Animate application. When a victim opens such a file, the application's parsing routine executes without proper bounds checking, causing the program to read memory locations that contain sensitive information. The attack is particularly concerning because it operates within the context of the current user, meaning that any information accessible to that user's process can potentially be disclosed. This includes configuration data, temporary files, or other sensitive information that might be stored in adjacent memory locations. The vulnerability represents a significant risk to organizations where employees might inadvertently open malicious files from untrusted sources, potentially leading to data breaches or system compromise.
From an operational impact perspective, this vulnerability creates a substantial risk to enterprise security environments where Adobe Animate is commonly used for multimedia development and animation creation. The out-of-bounds read can expose sensitive information that might include user session data, application configuration details, or other system-specific information that could aid in subsequent attacks. The vulnerability's requirement for user interaction makes it less likely to be exploited at scale compared to fully automated attacks, but it still represents a significant threat vector in targeted campaigns. Security teams must consider the potential for privilege escalation if the application runs with elevated privileges, as the disclosed information could potentially lead to more severe compromises. The vulnerability also impacts the integrity of the application's runtime environment, as memory corruption can potentially lead to application instability or further exploitation opportunities. Organizations should note that this vulnerability is particularly dangerous in environments where users have administrative privileges or access to sensitive data, as the disclosed information could be leveraged to gain deeper access to systems.
Mitigation strategies for this vulnerability should include immediate patching of Adobe Animate to version 21.0.4 or later, which contains the necessary memory bounds checking fixes. Organizations should implement strict file validation policies, particularly for animation files received from external sources or untrusted users. Network-based protections such as email filtering and web application firewalls can help prevent users from accessing malicious files before they reach their desktops. Security awareness training should emphasize the importance of not opening suspicious animation files, as this vulnerability specifically requires user interaction for exploitation. System administrators should monitor for any unusual file access patterns or memory usage that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1059 Command and Scripting Interpreter suggests that attackers might use the disclosed information to craft more sophisticated attacks. Regular security audits should include verification that Adobe Animate installations are properly patched and that users are not opening untrusted files. Additionally, implementing application whitelisting policies that restrict which applications can execute on the system can provide an additional layer of protection against exploitation attempts.