CVE-2017-18238 in Exempi
Summary
by MITRE
An issue was discovered in Exempi before 2.4.4. The TradQT_Manager::ParseCachedBoxes function in XMPFiles/source/FormatSupport/QuickTime_Support.cpp allows remote attackers to cause a denial of service (infinite loop) via crafted XMP data in a .qt file.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2017-18238 represents a critical denial of service flaw within the Exempi library, specifically affecting versions prior to 2.4.4. This issue resides within the TradQT_Manager::ParseCachedBoxes function located in XMPFiles/source/FormatSupport/QuickTime_Support.cpp, demonstrating how seemingly benign file parsing operations can be exploited to disrupt system availability. The flaw manifests when processing crafted XMP data embedded within .qt files, creating a scenario where legitimate file processing operations become trapped in infinite loops. This vulnerability directly impacts the stability and reliability of applications that depend on Exempi for handling QuickTime media files, as any attempt to parse a maliciously constructed .qt file will result in indefinite resource consumption and system unresponsiveness.
The technical nature of this vulnerability aligns with CWE-835, which specifically addresses infinite loops or iterations that can lead to denial of service conditions. The flaw operates by manipulating the parsing logic within the QuickTime support module, where the ParseCachedBoxes function fails to properly validate input data structures before attempting recursive processing. When malicious XMP metadata is embedded within a QuickTime container, the function's loop control mechanisms become compromised, causing the parser to repeatedly iterate through the same data segments without proper termination conditions. This behavior creates a classic denial of service scenario where system resources are consumed indefinitely, preventing legitimate processing of subsequent files and potentially leading to complete application hang or system instability.
From an operational perspective, this vulnerability presents significant risks to organizations relying on Exempi for media processing workflows, particularly in environments where automated file handling and batch processing are common. Attackers can exploit this weakness by crafting malicious .qt files containing specially formatted XMP data that triggers the infinite loop condition, effectively rendering processing systems unavailable to legitimate users. The impact extends beyond simple service disruption as it can affect content management systems, media processing pipelines, and digital asset management platforms that utilize Exempi for metadata extraction and file validation. The vulnerability can be particularly dangerous in automated environments where multiple files are processed sequentially, as a single malicious file can cause cascading failures throughout the entire processing pipeline, potentially affecting multiple concurrent operations.
The ATT&CK framework categorizes this vulnerability under T1499.004, which addresses "Endpoint Denial of Service" through the manipulation of application parsing logic. Organizations should implement immediate mitigations including updating to Exempi version 2.4.4 or later, which contains the necessary patches to prevent the infinite loop condition. Additional defensive measures include implementing file validation routines that check for suspicious XMP structures before processing, deploying sandboxing mechanisms for suspicious file types, and establishing monitoring protocols to detect unusual processing patterns that may indicate exploitation attempts. Network-level protections such as content filtering and file type validation can also serve as additional barriers to prevent malicious files from reaching vulnerable systems. Security teams should also consider implementing automated patch management processes to ensure rapid deployment of the security update across all affected systems, as the vulnerability can be exploited remotely without requiring user interaction or elevated privileges.