CVE-2022-35462 in OTFCC
Summary
by MITRE • 08/17/2022
OTFCC v0.10.4 was discovered to contain a heap-buffer overflow via /release-x64/otfccdump+0x6c0bc3.
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Analysis
by VulDB Data Team • 09/17/2022
The vulnerability identified as CVE-2022-35462 represents a critical heap-buffer overflow condition within OTFCC version 0.10.4, specifically manifesting at the memory address /release-x64/otfccdump+0x6c0bc3. This issue occurs within the OTFCC (OpenType Font Compiler Collection) toolset that processes OpenType font files and their associated data structures. The heap-buffer overflow vulnerability arises when the application processes malformed or specially crafted input files without proper bounds checking, allowing an attacker to write beyond the allocated heap memory boundaries. Such vulnerabilities are particularly dangerous in font processing applications since they can be triggered by simply opening or rendering a malicious font file, making them ideal candidates for remote code execution attacks through arbitrary code execution primitives.
The technical flaw stems from inadequate input validation and memory management practices within the OTFCC font processing pipeline. When the application attempts to parse font data structures, particularly those containing complex or malformed metadata, it fails to properly validate array indices or buffer sizes before performing memory operations. This allows an attacker to craft font files that cause the program to write data beyond the intended buffer boundaries, potentially corrupting adjacent heap memory structures. The vulnerability is classified as a heap-based buffer overflow according to CWE-121, which specifically addresses heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite heap memory. The memory corruption can lead to unpredictable program behavior, application crashes, or more severe consequences including privilege escalation and arbitrary code execution.
The operational impact of this vulnerability extends beyond simple application instability, as it creates potential attack vectors for adversaries seeking to compromise systems through font rendering processes. Since font files are commonly encountered in various applications including web browsers, desktop environments, and document viewers, an attacker could exploit this vulnerability by delivering malicious font files through email attachments, web pages, or file sharing platforms. The attack surface is broadened by the fact that many applications rely on font rendering libraries that may be vulnerable to similar issues, creating cascading effects across different software ecosystems. According to ATT&CK framework, this vulnerability could be leveraged under technique T1203 - Exploitation for Client Execution, where adversaries use vulnerabilities in applications to execute malicious code on target systems.
Mitigation strategies for CVE-2022-35462 should prioritize immediate patching of the OTFCC toolset to version 0.10.5 or later, which contains the necessary fixes for the heap-buffer overflow condition. Organizations should also implement defensive measures such as restricting font file processing in high-security environments, employing sandboxing techniques for font rendering operations, and monitoring for unusual memory allocation patterns or application crashes. Input validation should be enhanced to include bounds checking for all font data structures, particularly those related to metadata and font table processing. Security teams should also consider implementing network segmentation to limit exposure of systems that process font files, and establish incident response procedures for handling potential exploitation attempts. The vulnerability highlights the importance of proper memory management practices and input validation in font processing applications, emphasizing the need for regular security assessments of font rendering libraries and tools used in enterprise environments.