CVE-2024-56520: High Vulnerability in tc-lib-pdf-font

An issue was discovered in tc-lib-pdf-font before 2.6.4, as used in TCPDF before 6.8.0 and other products. Fonts are mishandled, e.g., FontBBox for Type 1 and TrueType fonts is misparsed. This vulnerability is classified as high severity with a CVSS score of 7.3, indicating a significant risk to affected systems.

Risk to organizations includes the potential for unauthorized access and manipulation of PDF documents, which could lead to data integrity issues. The vulnerability has not been publicly exploited, but organizations should remain vigilant.

Organizations should prioritize patching immediately. The affected versions require updates to mitigate this vulnerability effectively.

This vulnerability has a published date of December 27, 2024, and is currently marked as deferred in the CVE database.

Vulnerability Details

An issue was discovered in tc-lib-pdf-font before 2.6.4, as used in TCPDF before 6.8.0 and other products. Fonts are mishandled, e.g., FontBBox for Type 1 and TrueType fonts is misparsed. This vulnerability has a CVSS score of 7.3, classified as high severity. The publication date is December 27, 2024. The vulnerability has been assigned a CVE identifier for tracking purposes.

Technical Analysis

The root cause of this vulnerability lies in the mishandling of font parsing in tc-lib-pdf-font. This leads to incorrect parsing of FontBBox in Type 1 and TrueType fonts, which can result in improper rendering or manipulation of PDF documents.

The attack vector is network-based, with low complexity and no privileges required for exploitation. User interaction is also not necessary, making this vulnerability particularly concerning. The impact on confidentiality, integrity, and availability is rated as low.

Risk & Impact Analysis

Real-world deployment risk includes the potential for attackers to manipulate PDF documents, which can have significant implications for organizations relying on this technology. The blast radius could extend to all systems utilizing affected versions of tc-lib-pdf-font, increasing the urgency for remediation.

Organizations should address this vulnerability in their priority patch cycle. Given the high CVSS score, this vulnerability necessitates immediate attention to avoid potential exploitation.

Exploitation Status

Affected Versions

All versions prior to vendor patch for tc-lib-pdf-font 2.6.4 and TCPDF 6.8.0 are affected by this vulnerability.

Mitigation & Remediation

Organizations should apply the latest patches for tc-lib-pdf-font and TCPDF to mitigate this vulnerability. If immediate updates are not possible, it is recommended to implement configuration hardening and access controls to limit exposure.

For further guidance on testing and validating security measures, organizations may consider engaging in penetration testing to identify potential weaknesses.

Detection Guidance

Organizations should monitor logs for unusual activities related to PDF document generation and parsing. Additionally, behavioral anomalies in document handling should be assessed to detect potential abuses of this vulnerability.

AppSecure Threat Intelligence Insight

The long-term significance of this vulnerability highlights the importance of secure font handling in document processing systems. As organizations continue to rely on PDF generation, ensuring the integrity of font parsing mechanisms is critical. Security teams should prioritize regular assessments and updates to their libraries to mitigate similar vulnerabilities.

For more insights on vulnerability management, organizations may benefit from reviewing our vulnerability management program design and best practices.

Additionally, enhanced security through penetration testing methodology can uncover potential weaknesses in the implementation.

As organizations adapt to new threats, understanding the implications of vulnerabilities like CVE-2024-56520 will be crucial for maintaining robust security postures.