CVE-2017-6850 in Jasper
Summary
by MITRE
The jp2_cdef_destroy function in jp2_cod.c in JasPer before 2.0.13 allows remote attackers to cause a denial of service (NULL pointer dereference) via a crafted image.
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Analysis
by VulDB Data Team • 09/09/2020
The vulnerability identified as CVE-2017-6850 represents a critical denial of service flaw within the JasPer library version 2.0.12 and earlier. This issue manifests in the jp2_cdef_destroy function located within the jp2_cod.c source file, which is part of the JasPer image processing library used for handling jpeg2000 format images. The vulnerability occurs when the library processes malformed or crafted jpeg2000 images that contain specific malformed cdef (color definition) structures, leading to a NULL pointer dereference during the image destruction process. This flaw affects applications that rely on JasPer for image processing, including web servers, image processing frameworks, and various multimedia applications that handle user-uploaded jpeg2000 files.
The technical exploitation of this vulnerability requires an attacker to craft a malicious jpeg2000 image file containing malformed color definition data that triggers the NULL pointer dereference when the jp2_cdef_destroy function attempts to process the corrupted data structure. This function is responsible for cleaning up color definition information during image destruction, but when it encounters improperly formatted cdef data, it attempts to dereference a NULL pointer, causing the application to crash and resulting in a denial of service condition. The vulnerability is classified under CWE-476 as a NULL pointer dereference, which is a common software flaw that occurs when a program attempts to access memory through a pointer that has not been properly initialized or has been set to NULL. This type of vulnerability is particularly dangerous in network services and applications that process untrusted input data, as it can be easily exploited to disrupt service availability.
The operational impact of CVE-2017-6850 extends beyond simple service disruption, as it can affect a wide range of applications that utilize the JasPer library for image processing. Systems running web applications, content management systems, image galleries, and multimedia platforms that accept jpeg2000 uploads are all at risk of being exploited. The vulnerability is particularly concerning because it can be triggered through simple file uploads, making it an attractive target for attackers seeking to perform denial of service attacks against web services. According to the MITRE ATT&CK framework, this vulnerability could be categorized under the T1499.004 technique for Network Denial of Service, as it allows remote attackers to cause service disruption through crafted input data. The impact is significant as it can lead to complete service unavailability, requiring system administrators to restart affected services and potentially resulting in extended downtime for users.
Mitigation strategies for CVE-2017-6850 primarily focus on upgrading to JasPer version 2.0.13 or later, which contains the necessary patches to prevent the NULL pointer dereference. Organizations should conduct comprehensive vulnerability assessments to identify all systems using vulnerable versions of JasPer and prioritize their remediation. Additionally, implementing input validation and sanitization measures can provide an additional layer of protection by filtering out malformed image files before they reach the image processing libraries. Network segmentation and access controls should be enforced to limit exposure of systems that process untrusted image uploads. Regular security monitoring and log analysis should be implemented to detect potential exploitation attempts, while maintaining up-to-date threat intelligence feeds to identify emerging attack patterns targeting similar vulnerabilities in image processing libraries. The vulnerability demonstrates the importance of proper input validation and error handling in multimedia processing libraries, as even malformed image files can lead to system instability and service disruption.