CVE-2017-9936 in LibTIFF
Summary
by MITRE
In LibTIFF 4.0.8, there is a memory leak in tif_jbig.c. A crafted TIFF document can lead to a memory leak resulting in a remote denial of service attack.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2017-9936 represents a critical memory management flaw within the LibTIFF library version 4.0.8 specifically within the tif_jbig.c component responsible for handling JBIG compressed image data. This memory leak occurs when processing specially crafted TIFF files that contain malformed JBIG compression headers, creating a condition where allocated memory is not properly released during the decompression process. The flaw stems from inadequate resource cleanup mechanisms in the library's handling of compressed image data structures, particularly when encountering malformed input sequences that trigger unexpected code paths within the JBIG decoder implementation. The vulnerability is classified under CWE-401 as a failure to release memory resources, making it a classic example of a memory leak that can be exploited for denial of service attacks.
The operational impact of this vulnerability extends beyond simple resource consumption as it enables remote attackers to systematically deplete system memory through repeated processing of malicious TIFF files. When a vulnerable application processes the crafted input, the memory leak accumulates with each subsequent file processing, eventually leading to complete memory exhaustion and application crash. This makes the vulnerability particularly dangerous in server environments where applications may process untrusted TIFF files from external sources, such as web applications handling user uploads or content management systems processing image submissions. The remote nature of the attack means that an attacker can exploit this vulnerability without requiring local access to the target system, making it a significant concern for networked applications that utilize LibTIFF for image processing.
From an attack perspective, this vulnerability aligns with ATT&CK technique T1499.004 which involves network denial of service attacks through resource exhaustion. The memory leak behavior creates a predictable pattern where each processed file consumes additional memory without proper cleanup, allowing attackers to craft payloads that will cause progressive memory degradation. The vulnerability can be exploited through multiple vectors including web applications, email servers, or any system that processes TIFF files without proper input validation. Security practitioners should note that this vulnerability demonstrates the importance of proper resource management in image processing libraries and highlights the need for robust input sanitization and memory leak detection in multimedia processing components. The attack requires minimal sophistication as it only requires crafting a specific TIFF file structure that triggers the problematic code path in the JBIG decoder, making it a particularly dangerous vulnerability for widespread exploitation.
Mitigation strategies should focus on immediate library updates to versions that contain the memory leak fix, as well as implementing input validation measures that can detect and reject malformed TIFF files before they reach the vulnerable decoder. Organizations should also consider implementing resource limits and monitoring for memory consumption patterns that might indicate exploitation attempts. The fix typically involves proper memory deallocation in the JBIG decoder component and improved error handling for malformed input sequences. Additionally, deploying network-based intrusion detection systems that can identify suspicious TIFF file patterns and implementing application-level sandboxing for image processing operations can provide additional layers of protection against this type of remote denial of service attack.