CVE-2014-0238 in Mac OS X
Summary
by MITRE
The cdf_read_property_info function in cdf.c in the Fileinfo component in PHP before 5.4.29 and 5.5.x before 5.5.13 allows remote attackers to cause a denial of service (infinite loop or out-of-bounds memory access) via a vector that (1) has zero length or (2) is too long.
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Analysis
by VulDB Data Team • 02/20/2022
The vulnerability identified as CVE-2014-0238 represents a critical flaw in PHP's Fileinfo component that affects versions prior to 5.4.29 and 5.5.x prior to 5.5.13. This issue resides within the cdf_read_property_info function in the cdf.c file, which is responsible for handling Compound Document File format parsing operations. The vulnerability manifests when the function processes malformed Compound Document File structures that contain either zero-length entries or excessively long data segments, creating a dangerous condition that can be exploited by remote attackers to disrupt service availability.
The technical exploitation of this vulnerability occurs through the manipulation of Compound Document File parsing logic where the cdf_read_property_info function fails to properly validate input parameters before processing. When encountering a vector with zero length or an excessively long structure, the function enters an infinite loop scenario or triggers out-of-bounds memory access conditions. This parsing failure stems from inadequate boundary checking and input validation mechanisms within the Compound Document File parser, which is commonly used by PHP applications to determine file types and metadata. The flaw demonstrates characteristics consistent with CWE-129, which addresses improper validation of array indices and buffer overflows, and also aligns with CWE-770, addressing allocation of resources without limits or with inadequate limits.
The operational impact of this vulnerability extends beyond simple denial of service to potentially compromise entire PHP applications and web servers. Remote attackers can leverage this weakness to consume excessive system resources through infinite loops, leading to server resource exhaustion and application unavailability. Additionally, the out-of-bounds memory access conditions could potentially be exploited to cause application crashes or, in more sophisticated scenarios, could be combined with other vulnerabilities to achieve arbitrary code execution. This makes the vulnerability particularly dangerous in web environments where PHP applications process untrusted file uploads or metadata from external sources, as the attack surface expands to include any application that utilizes the Fileinfo extension for file type detection.
Organizations affected by this vulnerability should implement immediate mitigations including upgrading to patched PHP versions, specifically PHP 5.4.29 or PHP 5.5.13 and later, which contain the necessary fixes to address the input validation issues in the Compound Document File parser. System administrators should also consider implementing additional defensive measures such as input sanitization for file uploads, rate limiting for file processing operations, and monitoring for unusual resource consumption patterns that might indicate exploitation attempts. The vulnerability's classification under the ATT&CK framework would place it within the privilege escalation and denial of service categories, specifically addressing techniques related to resource exhaustion and application-level exploitation. Regular security assessments and vulnerability scanning should be conducted to ensure all PHP installations are properly patched and that no legacy systems remain exposed to this or similar parsing vulnerabilities.