CVE-2012-1131 in iOS
Summary
by MITRE
FreeType before 2.4.9, as used in Mozilla Firefox Mobile before 10.0.4 and other products, on 64-bit platforms allows remote attackers to cause a denial of service (invalid heap read operation and memory corruption) or possibly execute arbitrary code via vectors related to the cell table of a font.
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Analysis
by VulDB Data Team • 05/01/2018
The vulnerability identified as CVE-2012-1131 represents a critical heap memory corruption issue within the FreeType font rendering library that affects multiple applications including Mozilla Firefox Mobile. This flaw exists in FreeType versions prior to 2.4.9 and specifically manifests on 64-bit computing platforms where the font processing engine encounters malformed font data structures. The vulnerability stems from improper handling of font cell table data structures during the rendering process, creating opportunities for attackers to manipulate memory operations through carefully crafted malicious fonts. The issue falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read errors that can lead to memory corruption and potential code execution.
The technical exploitation of this vulnerability occurs when FreeType processes font files containing malformed cell table entries that trigger invalid heap read operations. During font rendering on 64-bit systems, the library fails to properly validate the bounds of cell table data structures, allowing attackers to craft font files that cause memory corruption when the rendering engine attempts to access memory locations outside the allocated buffer boundaries. This memory corruption can manifest as either denial of service through application crashes or more severe outcomes including arbitrary code execution within the context of the vulnerable application. The attack vector specifically targets the font processing pipeline where applications like Firefox Mobile load and render font files, making it particularly dangerous in mobile environments where users may encounter malicious fonts in emails, web pages, or downloaded content.
The operational impact of CVE-2012-1131 extends beyond simple denial of service scenarios to encompass potential remote code execution capabilities that could allow attackers to compromise affected systems. Mobile applications using vulnerable FreeType versions become susceptible to attacks that could lead to complete system compromise, especially when users encounter malicious fonts in web content or email attachments. The vulnerability is particularly concerning in mobile environments where users have less control over their software ecosystem and may encounter untrusted font content more frequently than in desktop environments. Security researchers have classified this vulnerability under ATT&CK technique T1068 which involves exploiting privileges to gain code execution, while the memory corruption aspects align with T1203 which addresses execution through modification of loaded modules.
Mitigation strategies for CVE-2012-1131 primarily focus on updating to FreeType version 2.4.9 or later, which contains the necessary patches to properly validate font cell table boundaries and prevent heap memory corruption. System administrators should prioritize updating Firefox Mobile to version 10.0.4 or higher, as this release includes the patched FreeType library. Additional protective measures include implementing font validation mechanisms at the application level, deploying sandboxing techniques to limit the impact of potential exploitation, and configuring web browsers to restrict font loading from untrusted sources. Organizations should also consider implementing network-level controls to filter potentially malicious font content and regularly audit their software dependencies to identify other vulnerable components that may be susceptible to similar memory corruption vulnerabilities. The fix addresses the root cause by implementing proper bounds checking and memory validation procedures that prevent out-of-bounds heap access during font processing operations, aligning with industry best practices for secure software development and memory safety protocols.