CVE-2014-9662 in FreeType
Summary
by MITRE
cff/cf2ft.c in FreeType before 2.5.4 does not validate the return values of point-allocation functions, which allows remote attackers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via a crafted OTF font.
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Analysis
by VulDB Data Team • 03/08/2022
The vulnerability identified as CVE-2014-9662 resides within the FreeType font rendering library, specifically in the cff/cf2ft.c module. This issue affects FreeType versions prior to 2.5.4 and represents a critical security flaw that can be exploited remotely through maliciously crafted OpenType font files. The vulnerability stems from inadequate validation of point-allocation function return values during font processing operations, creating a fundamental weakness in the library's memory management and input handling mechanisms.
The technical flaw manifests when FreeType processes Compact Font Format (CFF) fonts, particularly within the cf2ft.c component responsible for converting CFF data structures into font tables. The library fails to properly validate the return values from point-allocation functions that are essential for managing memory resources during font rendering. When these functions return unexpected values or indicate allocation failures, the code continues execution without proper error handling, leading to heap-based buffer overflow conditions. This occurs because the application assumes successful memory allocation and proceeds to write data beyond allocated buffer boundaries, potentially corrupting adjacent memory regions and causing unpredictable behavior.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enable more sophisticated attacks. Remote attackers can craft malicious OTF font files that trigger the buffer overflow condition when processed by vulnerable FreeType implementations. This allows adversaries to cause application crashes, system instability, or potentially execute arbitrary code depending on the specific memory corruption patterns. The vulnerability affects any system or application that relies on FreeType for font rendering, including web browsers, desktop applications, and server software processing font files. The heap-based nature of the overflow provides attackers with opportunities to manipulate memory layout and potentially achieve privilege escalation or code execution in vulnerable environments.
Mitigation strategies for CVE-2014-9662 primarily involve upgrading to FreeType version 2.5.4 or later, which includes proper validation of point-allocation function return values. System administrators should implement comprehensive patch management procedures to ensure all affected applications using FreeType are updated promptly. Additionally, implementing strict input validation and sandboxing measures for font processing operations can provide defense-in-depth protection. Organizations should also consider restricting font file processing to trusted sources and implementing automated scanning for malicious font files in network traffic. This vulnerability aligns with CWE-129, which addresses insufficient validation of length of input buffers, and maps to ATT&CK technique T1203, representing exploitation of software vulnerabilities for privilege escalation. The remediation process should include thorough testing of updated libraries to ensure compatibility with existing applications while maintaining security posture against similar memory corruption vulnerabilities in font rendering systems.