CVE-2021-21074 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, which represents improper validation of array indices or buffer bounds. This flaw exists within the software's handling of file parsing operations, specifically when processing malformed or specially crafted files that contain malicious data structures. The vulnerability stems from insufficient bounds checking mechanisms that fail to validate the size and integrity of data elements before accessing memory locations. An attacker can exploit this weakness by crafting a malicious file that triggers the out-of-bounds read condition during normal file processing operations. This vulnerability is classified as a remote code execution risk under the ATT&CK framework category of T1203, where adversaries leverage software vulnerabilities to execute arbitrary code. The attack requires user interaction as the victim must open the malicious file for exploitation to occur, making it a typical social engineering target. The security implications of this vulnerability extend beyond simple information disclosure, as the out-of-bounds read can potentially expose sensitive memory contents including cryptographic keys, user credentials, or system information that could be leveraged for further attacks. The vulnerability exists in the application's file parsing logic where it fails to properly validate the length of arrays or buffers before attempting to read from memory locations, creating a potential pathway for attackers to extract confidential data from the application's memory space. This type of vulnerability is particularly dangerous in creative software environments where users frequently open files from untrusted sources, making the attack surface particularly broad.
The technical exploitation of CVE-2021-21074 requires careful crafting of file structures that cause the application to attempt reading memory beyond allocated boundaries. When Adobe Animate processes a malicious file, the parsing routines fail to validate the integrity of the data structure, leading to memory access violations that can result in information disclosure. The vulnerability operates within the context of the current user's privileges, meaning that successful exploitation would only allow access to data that the user has access to, but could still result in significant information leakage. This type of vulnerability is particularly challenging to detect during normal operation as the out-of-bounds read may not immediately crash the application but could silently leak information. The attack vector requires that the user explicitly open the malicious file, which makes it susceptible to social engineering tactics where attackers might disguise the file as legitimate creative assets or documents. The vulnerability's impact is amplified by the fact that Adobe Animate is commonly used for creating multimedia content, making users more likely to open files from unknown sources, especially in collaborative environments or when downloading content from online repositories. The implementation of proper bounds checking and input validation would prevent this vulnerability by ensuring that all array accesses are validated against the actual size of the allocated memory regions.
Organizations and individual users should immediately update to Adobe Animate version 21.0.4 or later to remediate this vulnerability, as the update contains proper bounds checking mechanisms that prevent out-of-bounds memory access. System administrators should implement strict file validation policies and educate users about the risks of opening untrusted files, particularly in creative software environments. Security monitoring should include detection of suspicious file opening activities and unusual memory access patterns that could indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory safety practices in software development, aligning with security standards such as the OWASP Top Ten and NIST cybersecurity guidelines. Organizations should also consider implementing application whitelisting policies that restrict execution of untrusted files, particularly in environments where creative software is commonly used. Regular security assessments should be conducted to identify similar vulnerabilities in other creative and multimedia applications that may be susceptible to similar out-of-bounds read conditions. The incident highlights the critical need for comprehensive software security testing including fuzzing and memory safety analysis to identify potential vulnerabilities before they can be exploited in the wild. Users should be trained to recognize phishing attempts that might deliver malicious files disguised as legitimate creative assets or project files. The vulnerability's remediation through software updates emphasizes the importance of maintaining current security patches and implementing automated update mechanisms for all software components that handle user-provided data.