CVE-2021-36004 in InDesign
Summary
by MITRE • 07/30/2021
Adobe InDesign version 16.0 (and earlier) is affected by an Out-of-bounds Write vulnerability in the CoolType library. An unauthenticated attacker could leverage this vulnerability to achieve remote code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/06/2021
Adobe InDesign versions 16.0 and earlier contain a critical out-of-bounds write vulnerability within the CoolType library component that represents a significant security risk for users. This vulnerability falls under the CWE-787 Out-of-bounds Write classification, where the application fails to properly validate array indices or buffer boundaries before writing data. The CoolType library serves as Adobe's font handling system, responsible for rendering complex typography and font-related operations within the application. When processing specially crafted font files or embedded font data, the library does not adequately validate input parameters, leading to memory corruption that can be exploited by malicious actors.
The exploitability of this vulnerability requires user interaction through social engineering or phishing attacks where victims must open a malicious file containing crafted font data. This attack vector aligns with ATT&CK technique T1203, which involves gaining access through exploitation of a software vulnerability that requires user action. The remote code execution capability means that successful exploitation could allow an attacker to execute arbitrary code with the privileges of the current user, potentially leading to complete system compromise. The vulnerability is particularly concerning because InDesign is commonly used in professional environments where users may encounter untrusted font files from various sources, including online downloads, email attachments, or collaborative work environments.
The operational impact of this vulnerability extends beyond individual user compromise to affect enterprise security postures and workflow integrity. Organizations using Adobe InDesign for creative work, publishing, or design projects face significant risk when users inadvertently open malicious files containing crafted fonts. The vulnerability affects the entire Adobe Creative Cloud ecosystem since CoolType is a shared library component. Security teams must consider the implications for document review processes, file sharing protocols, and user education regarding safe file handling practices. The exploitability requires user interaction but once triggered, the remote code execution capability provides attackers with persistent access to compromised systems, potentially enabling data exfiltration, lateral movement, or establishment of backdoors.
Mitigation strategies should focus on immediate patch management with Adobe's security updates and implementing defensive measures such as restricting user permissions, deploying application whitelisting policies, and establishing secure file handling procedures. Organizations should consider disabling automatic font loading features and implementing sandboxing mechanisms for document processing. Network-based protections such as intrusion detection systems should be configured to monitor for suspicious file types and potentially malicious font-related activity. Regular security awareness training should emphasize the dangers of opening untrusted files and the importance of verifying file sources before processing. Additionally, implementing file validation mechanisms that scan for potentially malicious font data and maintaining updated threat intelligence feeds can help detect and prevent exploitation attempts. The vulnerability highlights the importance of secure coding practices in font processing libraries and demonstrates how seemingly innocuous components like typography rendering can become attack vectors when proper input validation is absent.