CVE-2016-6223 in LibTIFF
Summary
by MITRE
The TIFFReadRawStrip1 and TIFFReadRawTile1 functions in tif_read.c in libtiff before 4.0.7 allows remote attackers to cause a denial of service (crash) or possibly obtain sensitive information via a negative index in a file-content buffer.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2016-6223 affects the libtiff library version 4.0.6 and earlier, specifically targeting the TIFFReadRawStrip1 and TIFFReadRawTile1 functions located in the tif_read.c source file. This flaw represents a classic buffer overflow condition that can be exploited through maliciously crafted TIFF image files. The vulnerability occurs when the library processes image data containing negative indices within file-content buffers, creating a scenario where memory access violations can occur during the reading process. The issue stems from insufficient input validation and boundary checking within the TIFF parsing routines, allowing attackers to manipulate the internal buffer management logic through crafted file structures.
The technical implementation of this vulnerability involves the manipulation of TIFF file headers and data structures to force the library into performing operations with negative array indices or invalid memory offsets. When these functions encounter negative values during buffer calculations, they can cause the application to access memory locations outside the intended buffer boundaries. This condition can lead to segmentation faults causing application crashes or potentially allow information disclosure if the invalid memory access reads from adjacent memory regions containing sensitive data. The vulnerability is particularly dangerous because it can be triggered through normal file processing operations without requiring special privileges or complex exploitation techniques.
The operational impact of CVE-2016-6223 extends across numerous applications and systems that rely on libtiff for image processing, including web servers, image editing software, digital asset management systems, and security scanning tools. When exploited, the vulnerability can cause denial of service conditions that disrupt legitimate service operations, potentially leading to system unavailability or application crashes. In some scenarios, the memory access violations might expose sensitive information from adjacent memory regions, though this information disclosure aspect is less common and depends on the specific memory layout and operating system environment. The vulnerability affects both client-side applications that process user-uploaded images and server-side systems that handle image processing workflows, making it particularly concerning for web applications and content management systems.
This vulnerability aligns with CWE-129, which addresses improper validation of array indices, and represents a specific instance of improper input validation in image processing libraries. The attack pattern follows typical remote code execution vectors from malformed file formats, and can be classified under ATT&CK technique T1203, which involves exploiting file format vulnerabilities in software applications. The remediation strategy focuses on upgrading to libtiff version 4.0.7 or later, which includes proper bounds checking and input validation mechanisms. Additionally, implementing proper file validation procedures, including early detection of malformed TIFF headers and limiting memory allocation based on file metadata, provides effective mitigation. Organizations should also consider implementing sandboxing mechanisms for image processing operations and deploying automated scanning systems to detect and prevent exploitation attempts through malicious file uploads.