CVE-2014-9669 in FreeType
Summary
by MITRE
Multiple integer overflows in sfnt/ttcmap.c in FreeType before 2.5.4 allow remote attackers to cause a denial of service (out-of-bounds read or memory corruption) or possibly have unspecified other impact via a crafted cmap SFNT table.
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Analysis
by VulDB Data Team • 03/08/2022
The vulnerability identified as CVE-2014-9669 represents a critical security flaw within the FreeType font rendering library, specifically affecting versions prior to 2.5.4. This issue resides in the sfnt/ttcmap.c component which handles cmap table processing within SFNT (Simple Font Number Table) font formats. The vulnerability stems from improper handling of integer overflow conditions during the parsing of cmap tables, which are essential components of font files that map character codes to glyph indices. These cmap tables are fundamental to font rendering across multiple operating systems and applications that rely on FreeType for font processing, making the impact of this vulnerability widespread and significant.
The technical flaw manifests as multiple integer overflows that occur when processing crafted cmap SFNT tables. When FreeType attempts to parse malformed cmap data, the integer overflow conditions cause the application to perform out-of-bounds memory reads or write operations that can result in memory corruption. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow and wraparound conditions, and more broadly under CWE-129, which covers insufficient validation of array indexing. The vulnerability is particularly dangerous because it can be triggered through font files that appear legitimate to users but contain maliciously crafted cmap table data designed to exploit the integer overflow conditions.
The operational impact of CVE-2014-9669 extends beyond simple denial of service scenarios to potentially enable more sophisticated attacks. Remote attackers can leverage this vulnerability to cause system instability through out-of-bounds memory access, leading to application crashes or system hangs that effectively result in denial of service. In some cases, the memory corruption could potentially be exploited to execute arbitrary code, though the specific exploitability varies based on system configurations and memory layouts. The vulnerability affects any application or system that utilizes FreeType for font rendering, including web browsers, office suites, desktop environments, and mobile applications, creating a substantial attack surface that spans multiple platforms and use cases.
Mitigation strategies for CVE-2014-9669 primarily focus on upgrading to FreeType version 2.5.4 or later, which contains the necessary patches to address the integer overflow conditions in cmap table processing. System administrators should prioritize updating FreeType libraries across all affected systems, particularly those running applications that handle untrusted font files from web sources or user uploads. Additional defensive measures include implementing strict font validation mechanisms, sandboxing font processing operations, and monitoring for unusual memory access patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation in font rendering libraries and aligns with ATT&CK technique T1068, which covers exploit for privilege escalation through the exploitation of software vulnerabilities. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates and reduce the window of exposure to such vulnerabilities.