CVE-2004-2223 in FsPHPGallery
Summary
by MITRE
FsPHPGallery before 1.2 allows remote attackers to cause a denial of service via an image with a large size attribute, which causes a crash when the server attempts to resize the image.
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Analysis
by VulDB Data Team • 06/25/2018
The vulnerability identified as CVE-2004-2223 affects FsPHPGallery versions prior to 1.2 and represents a classic denial of service flaw that exploits improper input validation in image processing functionality. This vulnerability resides in the gallery's image handling mechanism where it fails to properly validate or sanitize the size attributes of uploaded images before attempting to process them. The flaw specifically manifests when a remote attacker submits an image with an excessively large size attribute, triggering a server-side crash during the image resizing operation. This type of vulnerability falls under the category of resource exhaustion attacks that exploit the application's lack of proper bounds checking and input sanitization.
The technical implementation of this vulnerability demonstrates a fundamental flaw in the application's image processing pipeline where it blindly accepts and processes size parameters without adequate validation. When the server encounters an image with an oversized size attribute, it attempts to allocate memory or perform computational operations proportional to the specified dimensions, leading to system resource exhaustion or memory corruption that ultimately results in a crash. This behavior aligns with CWE-129, which addresses improper validation of array indices and buffer overflows, and represents a form of input validation weakness that can be exploited to disrupt service availability. The vulnerability operates at the application layer and requires no special privileges or authentication to exploit, making it particularly dangerous for publicly accessible web applications.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the overall stability and availability of the web server hosting the gallery application. When exploited successfully, the denial of service attack can render the entire gallery application inaccessible to legitimate users, effectively blocking access to all images and gallery functionality. The vulnerability creates a cascading effect where a single maliciously crafted image can cause the web server process to crash, potentially affecting other applications running on the same server instance. This type of attack pattern is consistent with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, and represents a common vector for disrupting web-based services in the absence of proper input validation controls.
Mitigation strategies for this vulnerability require immediate implementation of input validation controls within the FsPHPGallery application's image processing module. The most effective approach involves implementing strict bounds checking on size attributes before any image processing operations commence, ensuring that all dimension parameters fall within acceptable ranges. Additionally, the application should implement proper error handling and graceful degradation mechanisms to prevent crashes when malformed input is encountered. System administrators should also consider implementing rate limiting and file size restrictions on image uploads to further reduce the attack surface. The fix should include comprehensive sanitization of all image metadata and size attributes, with the application rejecting any input that exceeds predetermined maximum dimensions. This vulnerability underscores the critical importance of input validation and proper resource management in web applications, particularly those handling user-supplied media content, and serves as a reminder of the necessity for robust security controls in legacy web applications.