CVE-2010-3053 in FreeType
Summary
by MITRE
bdf/bdflib.c in FreeType before 2.4.2 allows remote attackers to cause a denial of service (application crash) via a crafted BDF font file, related to an attempted modification of a value in a static string.
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Analysis
by VulDB Data Team • 07/22/2018
The vulnerability identified as CVE-2010-3053 affects the FreeType font rendering library, specifically within the bdf/bdflib.c component. This issue represents a classic buffer overflow condition that occurs when processing Binary Desktop Format font files. The flaw manifests when the library attempts to handle malformed BDF font data, particularly in scenarios where the application tries to modify a static string value during font parsing operations. The vulnerability stems from inadequate input validation and memory management practices within the BDF font handling code, creating an exploitable condition that can be triggered remotely.
The technical implementation of this vulnerability involves a direct manipulation of memory structures during font file processing. When FreeType encounters a specially crafted BDF font file, the bdflib.c module attempts to modify a static string that is not properly allocated for modification. This results in an invalid memory access pattern that causes the application to crash. The flaw is classified as a memory corruption vulnerability and maps to CWE-121 in the Common Weakness Enumeration, which covers stack-based buffer overflow conditions. The vulnerability demonstrates characteristics of improper input validation where the system fails to properly sanitize font file data before attempting to process it, leading to a denial of service condition.
From an operational perspective, this vulnerability presents a significant risk to systems that rely on FreeType for font rendering, particularly web servers, desktop applications, and any software that processes untrusted font files. Attackers can exploit this weakness by crafting malicious BDF font files and delivering them through various attack vectors such as web downloads, email attachments, or compromised websites. The impact of exploitation results in immediate application termination, effectively causing a denial of service that can disrupt legitimate user access to services. The vulnerability is particularly concerning because it can be triggered without requiring any special privileges or user interaction, making it a high-severity threat in environments where font rendering is a common operation. The ATT&CK framework categorizes this as a denial of service attack technique under the T1499 sub-technique for network denial of service, as it specifically targets application stability through malformed input processing.
Mitigation strategies for CVE-2010-3053 should focus on immediate software updates to FreeType version 2.4.2 or later, which contains the necessary patches to address the memory corruption issue. Organizations should also implement input validation controls that filter or reject suspicious font files before they reach the FreeType library. Network-based mitigations can include implementing content filtering solutions that scan for known malicious font file patterns and blocking their transmission. Additionally, system administrators should consider restricting font file processing to trusted sources only and implementing sandboxing techniques to isolate font rendering operations from core system processes. Regular security audits of font handling components and monitoring for unusual application crashes or memory access patterns can help detect exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper memory management in font rendering libraries and the need for comprehensive input validation to prevent similar issues in other software components that handle external data processing.