CVE-2016-9536 in macOS
Summary
by MITRE
tools/tiff2pdf.c in libtiff 4.0.6 has out-of-bounds write vulnerabilities in heap allocated buffers in t2p_process_jpeg_strip(). Reported as MSVR 35098, aka "t2p_process_jpeg_strip heap-buffer-overflow."
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Analysis
by VulDB Data Team • 11/20/2022
The vulnerability identified as CVE-2016-9536 represents a critical heap buffer overflow condition within the libtiff library version 4.0.6, specifically affecting the tiff2pdf conversion utility. This issue manifests in the tools/tiff2pdf.c file within the t2p_process_jpeg_strip() function, where improper bounds checking allows maliciously crafted TIFF files to trigger memory corruption during JPEG strip processing. The vulnerability stems from insufficient validation of buffer boundaries when handling heap-allocated memory regions, creating opportunities for attackers to write data beyond the allocated buffer limits.
The technical flaw operates through a classic buffer overflow mechanism where the t2p_process_jpeg_strip() function fails to properly verify the size of JPEG data strips before copying them into pre-allocated heap buffers. This oversight enables an attacker to craft TIFF files containing oversized JPEG data that exceeds the intended buffer capacity, resulting in memory corruption that can overwrite adjacent heap memory regions. The vulnerability is particularly dangerous because it occurs during the conversion process from TIFF to PDF format, making it exploitable when applications process untrusted image files through the affected library components.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can lead to arbitrary code execution when exploited successfully. Attackers can leverage this heap buffer overflow to manipulate program execution flow by overwriting critical memory structures or function pointers within the heap. The vulnerability affects any application that utilizes libtiff 4.0.6 for TIFF to PDF conversion, including document management systems, image processing software, and various enterprise applications that handle TIFF file conversions. This makes the attack surface particularly wide and impactful across multiple industries and software domains.
Mitigation strategies for CVE-2016-9536 should prioritize immediate patching of libtiff to versions 4.0.7 or later, where the buffer overflow conditions have been addressed through proper bounds checking implementation. Organizations should also implement input validation measures that restrict the size and format of TIFF files processed through affected systems, particularly when handling untrusted user uploads or external file sources. Additional defensive measures include deploying heap-based memory protection mechanisms such as stack canaries and address space layout randomization to reduce exploit reliability. The vulnerability aligns with CWE-121, heap-based buffer overflow, and could potentially map to attack techniques in the ATT&CK framework under the T1059 category for execution through compromised applications. Regular security assessments and vulnerability scanning should be conducted to ensure complete remediation across all systems utilizing the affected library components.