CVE-2007-6356 in exiftags
Summary
by MITRE
exiftags before 1.01 allows attackers to cause a denial of service (infinite loop) via recursive IFD references in the EXIF data in a JPEG image.
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Analysis
by VulDB Data Team • 08/02/2019
The vulnerability identified as CVE-2007-6356 affects the exiftags utility version 1.00 and earlier, presenting a significant denial of service risk through infinite loop exploitation via recursive IFD references within EXIF metadata of JPEG images. This flaw resides in the processing logic of the exiftags tool which is designed to extract and display EXIF metadata from digital photographs. The vulnerability manifests when the utility encounters JPEG files containing malformed EXIF data with recursive IFD (Image File Directory) references that create circular dependencies in the metadata structure.
The technical implementation of this vulnerability stems from insufficient validation and loop detection mechanisms within the exiftags parsing algorithm. When processing JPEG images with recursive IFD references, the utility enters an infinite loop as it attempts to traverse the circular metadata structure without proper termination conditions. This occurs because the parsing routine fails to maintain a reference tracking mechanism to identify previously visited IFD entries, causing it to repeatedly process the same metadata segments indefinitely. The flaw aligns with CWE-835, which specifically addresses infinite loops in software implementations where loop termination conditions are inadequate or missing.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited by malicious actors to consume system resources and potentially cause system instability. Attackers can craft specially formatted JPEG images containing recursive IFD references that, when processed by vulnerable exiftags versions, will cause the utility to hang indefinitely. This resource exhaustion scenario can be particularly problematic in automated environments where exiftags is invoked programmatically, as it may lead to complete system unresponsiveness or denial of service for legitimate users. The vulnerability also demonstrates characteristics aligned with ATT&CK technique T1499.004, which involves resource exhaustion attacks through malicious file processing.
Mitigation strategies for CVE-2007-6356 require immediate patching of the exiftags utility to version 1.01 or later, which includes proper loop detection and termination mechanisms for IFD traversal. System administrators should implement input validation measures to filter JPEG files with suspicious EXIF metadata before processing them through exiftags or similar utilities. Additionally, deploying automated monitoring systems to detect and alert on abnormal processing times or resource consumption patterns when handling image metadata can provide early detection of exploitation attempts. Organizations should also consider implementing sandboxed environments for image processing tasks to contain potential denial of service impacts and ensure that vulnerable systems are isolated from critical network services to minimize the attack surface.