CVE-2021-21076 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 represents a significant security risk for users who may encounter maliciously crafted files. This vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions where an application attempts to access memory beyond the bounds of a valid buffer. The flaw manifests when the software processes malformed input files, particularly those designed to exploit the buffer boundary violation during parsing operations. The vulnerability is classified as an information disclosure issue because it allows attackers to read memory contents that should remain protected, potentially exposing sensitive data such as system credentials, application memory structures, or other confidential information.
The exploitation of this vulnerability requires user interaction, meaning that an attacker must convince a victim to open a specifically crafted malicious file. This user interaction requirement places the vulnerability in the context of social engineering attacks where the malicious file might be delivered through email attachments, compromised websites, or other attack vectors designed to entice users into executing the file. The attack vector aligns with ATT&CK technique T1204.002 which involves user execution through malicious files, making this vulnerability particularly concerning for organizations that may not maintain strict file filtering policies. The out-of-bounds read occurs during the normal processing flow of Adobe Animate when it attempts to parse file headers or content structures, causing the application to read memory locations that extend beyond the allocated buffer boundaries.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked memory contents could potentially include cryptographic keys, session tokens, or other sensitive data that could be leveraged for further attacks. The fact that this vulnerability affects the current user context means that the disclosed information would be limited to the memory space accessible to the Adobe Animate process, but this still represents a significant compromise of user privacy and system security. Attackers could potentially use the leaked information to conduct more sophisticated attacks such as credential harvesting, privilege escalation, or even to bypass security controls within the application itself. The vulnerability's presence in Adobe Animate specifically affects users who work with multimedia content and may be targeted through file-based attacks that exploit the application's file parsing capabilities.
Organizations should prioritize updating their Adobe Animate installations to versions that address this vulnerability, as the out-of-bounds read condition creates a persistent risk for users who may encounter malicious files in their daily operations. The recommended mitigation strategy involves immediate deployment of patches from Adobe, which would correct the buffer boundary checking mechanisms within the application's file parsing routines. Additionally, users should implement defensive measures such as restricting file execution from untrusted sources, implementing application whitelisting policies, and conducting regular security awareness training to reduce the risk of successful exploitation through social engineering. Security monitoring should also be enhanced to detect unusual file access patterns or memory read operations that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and boundary checking in software applications, particularly in multimedia processing tools that handle untrusted file formats from diverse sources.