CVE-2010-2808 in FreeType
Summary
by MITRE
Buffer overflow in the Mac_Read_POST_Resource function in base/ftobjs.c in FreeType before 2.4.2 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via a crafted Adobe Type 1 Mac Font File (aka LWFN) font.
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Analysis
by VulDB Data Team • 09/23/2021
The vulnerability identified as CVE-2010-2808 represents a critical buffer overflow flaw within the FreeType font rendering library, specifically affecting versions prior to 2.4.2. This issue resides in the Mac_Read_POST_Resource function located in the base/ftobjs.c source file, which processes Adobe Type 1 Mac Font files with the LWFN extension. The flaw stems from inadequate input validation when handling malformed font data, creating a scenario where maliciously crafted font files can trigger memory corruption. The vulnerability operates through the improper handling of font resource data during the parsing of PostScript font tables, particularly when processing the POST resource structure that contains font metrics and glyph information. This represents a classic buffer overflow condition where the application writes beyond the allocated memory boundaries, potentially leading to unpredictable behavior.
The technical exploitation of this vulnerability occurs when a vulnerable FreeType library processes a specially crafted Adobe Type 1 Mac Font file that contains malformed POST resource data. The buffer overflow manifests during the parsing of font metrics and glyph information within the Mac_Read_POST_Resource function, where insufficient bounds checking allows an attacker to overwrite adjacent memory locations. This memory corruption can result in application crashes due to segmentation faults or more dangerously, potentially enable arbitrary code execution if the overflow can be carefully controlled to overwrite critical program execution pointers. The vulnerability is particularly concerning because it affects the core font processing functionality that many applications rely upon, including web browsers, office suites, and graphic design tools that utilize FreeType for font rendering.
The operational impact of CVE-2010-2808 extends beyond simple denial of service scenarios to encompass potential remote code execution capabilities, making it a significant security concern for systems processing untrusted font content. Attackers can leverage this vulnerability by delivering malicious font files through various attack vectors including email attachments, web downloads, or malicious websites that automatically render fonts. The vulnerability affects a wide range of applications that depend on FreeType for font handling, including popular web browsers like Internet Explorer, Firefox, and Chrome, as well as desktop applications such as Adobe Acrobat Reader, Microsoft Office, and various graphic design suites. This widespread impact creates a substantial attack surface where a single vulnerable font file can compromise multiple applications and systems. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and can be mapped to ATT&CK technique T1059.007 for execution through font rendering processes, making it particularly dangerous in targeted attack scenarios.
Mitigation strategies for CVE-2010-2808 primarily focus on immediate remediation through software updates to FreeType version 2.4.2 or later, which contains the necessary patches to address the buffer overflow condition. Organizations should implement comprehensive patch management processes to ensure all systems utilizing FreeType font libraries receive updates promptly. Additional defensive measures include implementing strict font validation policies that reject or quarantine suspicious font files, particularly those with unusual extensions or originating from untrusted sources. Network-level protections such as web application firewalls and content filtering systems can help prevent the delivery of malicious font files to user systems. Application sandboxing and privilege separation techniques can limit the damage if exploitation occurs, while regular security audits should verify that no legacy applications remain vulnerable. The vulnerability demonstrates the critical importance of input validation in font processing libraries and serves as a reminder of the security implications of font rendering components in modern software ecosystems, where seemingly benign file formats can become attack vectors for sophisticated exploitation techniques.