CVE-2017-7596 in LibTIFF
Summary
by MITRE
LibTIFF 4.0.7 has an "outside the range of representable values of type float" undefined behavior issue, which might allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted image.
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Analysis
by VulDB Data Team • 11/28/2022
The vulnerability identified as CVE-2017-7596 affects LibTIFF version 4.0.7 and represents a critical undefined behavior flaw that stems from improper handling of floating-point values during image processing operations. This issue manifests when the library encounters image data that contains values outside the range of representable values for the float type, creating a scenario where the application's behavior becomes unpredictable and potentially exploitable. The vulnerability exists within the TIFF image parsing functionality, specifically in how the library processes certain pixel data formats that may contain malformed or maliciously constructed floating-point values.
The technical nature of this vulnerability places it squarely within the realm of undefined behavior as defined by the CWE-758 weakness classification, which occurs when code relies on unspecified behavior that can lead to unpredictable results. When processing crafted TIFF images, the LibTIFF library fails to properly validate floating-point values against the limits of the float data type, allowing attackers to inject values that exceed the representable range. This condition can trigger memory corruption patterns or floating-point exception handling issues that ultimately result in application termination. The flaw is particularly concerning because it operates at the parsing layer where the library processes external input, making it susceptible to remote exploitation through crafted image files delivered via web services, file sharing platforms, or other attack vectors that involve TIFF image processing.
From an operational perspective, this vulnerability presents significant risk to systems that rely on LibTIFF for image processing workflows, including web applications, content management systems, digital asset management platforms, and any software that accepts user-uploaded TIFF images. The impact ranges from denial of service conditions that can disrupt legitimate service operations to potential information disclosure or arbitrary code execution scenarios depending on the specific implementation details and memory layout of the affected systems. The vulnerability can be exploited remotely without requiring authentication, making it particularly dangerous for web-facing applications that process user-provided content. Attackers can craft malicious TIFF files that, when processed by vulnerable applications, will cause the target software to crash or behave unpredictably, potentially leading to complete service disruption.
Mitigation strategies for CVE-2017-7596 should prioritize immediate patching of affected LibTIFF versions to the latest stable releases that contain fixes for the undefined behavior issue. Organizations should implement comprehensive input validation measures that sanitize all TIFF image data before processing, including implementing strict bounds checking for floating-point values and rejecting images that contain suspicious or malformed data structures. Network segmentation and application firewalls can provide additional layers of protection by limiting access to image processing services and monitoring for unusual patterns in image file handling. The ATT&CK framework categorizes this vulnerability under the T1203 technique for "Exploitation for Defense Evasion" and T1499 for "Endpoint Denial of Service" when considering how attackers might leverage such flaws to maintain persistent access or disrupt services. Security monitoring should focus on detecting abnormal application crashes or restarts that could indicate exploitation attempts, while regular vulnerability assessments should verify that all systems using LibTIFF have been updated to versions that address this specific undefined behavior condition.