CVE-2022-24092 in Acrobat Reader
Summary
by MITRE • 03/18/2022
Acrobat Reader DC version 21.007.20099 (and earlier), 20.004.30017 (and earlier) and 17.011.30204 (and earlier) are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious font file.
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Analysis
by VulDB Data Team • 03/23/2022
This vulnerability represents a critical out-of-bounds write flaw in Adobe Acrobat Reader DC across multiple version ranges including 21.007.20099 and earlier, 20.004.30017 and earlier, and 17.011.30204 and earlier. The flaw manifests when processing maliciously crafted font files, specifically within the font handling components of the application. This type of vulnerability falls under CWE-787 Out-of-bounds Write which is classified as a memory safety issue that can lead to arbitrary code execution when properly exploited. The vulnerability requires user interaction as the attack vector necessitates the victim opening a specifically crafted malicious font file, making it a typical targeted attack scenario that aligns with ATT&CK technique T1203 Exploitation for Client Execution.
The technical implementation of this vulnerability occurs within the font parsing and rendering subsystem of Acrobat Reader, where insufficient bounds checking allows an attacker to write data beyond the allocated memory buffer. When a user opens a malicious font file, the application's font parser fails to properly validate the size or structure of font data, enabling an attacker to overflow memory buffers and potentially overwrite adjacent memory regions. This overflow can corrupt program execution flow, potentially allowing an attacker to inject and execute arbitrary code within the context of the current user's privileges. The attack requires the victim to actively open the malicious file, which makes social engineering a critical component of successful exploitation.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a potential foothold for more sophisticated attacks within the victim's environment. Since the exploitation requires user interaction, attackers typically employ social engineering techniques to deliver malicious font files through email attachments, compromised websites, or other delivery mechanisms. The vulnerability affects multiple versions of Acrobat Reader, indicating a widespread exposure across different release cycles, which increases the potential attack surface significantly. Organizations using these vulnerable versions face substantial risk as attackers can leverage this vulnerability to gain unauthorized access to sensitive documents, potentially leading to data breaches or further compromise of the user's system through additional attack vectors.
Mitigation strategies should prioritize immediate patching of all affected Acrobat Reader versions to address the root cause of the vulnerability. Organizations should implement strict file validation policies that prevent automatic opening of potentially malicious font files, particularly those with unusual extensions or from untrusted sources. Network-based defenses such as email filtering and web proxy rules can help prevent delivery of malicious font files to users. Additionally, user education regarding the dangers of opening unexpected attachments and the importance of verifying file sources should be emphasized. Security monitoring should focus on detecting unusual file access patterns and potential exploitation attempts, while endpoint protection solutions should be configured to detect suspicious font file processing activities. The vulnerability's classification as a remote code execution flaw makes it particularly dangerous, requiring comprehensive defense-in-depth strategies that combine technical controls with user awareness training to effectively mitigate the risk.