CVE-2014-3480 in Mac OS X
Summary
by MITRE
The cdf_count_chain function in cdf.c in file before 5.19, as used in the Fileinfo component in PHP before 5.4.30 and 5.5.x before 5.5.14, does not properly validate sector-count data, which allows remote attackers to cause a denial of service (application crash) via a crafted CDF file.
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Analysis
by VulDB Data Team • 12/04/2025
The vulnerability identified as CVE-2014-3480 represents a critical denial of service flaw within PHP's Fileinfo component that affects versions prior to 5.4.30 and 5.5.14. This issue stems from improper validation of sector-count data within the Compound Document File (CDF) parsing functionality, specifically within the cdf_count_chain function located in cdf.c. The flaw occurs when PHP processes crafted CDF files that contain malformed sector-count information, leading to unpredictable application behavior and potential system crashes.
The technical exploitation of this vulnerability involves crafting malicious CDF files that contain manipulated sector-count values which, when processed by PHP's Fileinfo extension, trigger buffer overflows or memory corruption issues. This occurs because the cdf_count_chain function fails to properly validate the integrity of sector-count data before proceeding with file processing operations. The improper validation creates a condition where the application attempts to allocate memory or traverse data structures based on invalid sector-count values, ultimately resulting in application termination or system instability. This vulnerability falls under CWE-129, which describes improper validation of array indices, and specifically relates to issues in input validation and memory management within file parsing components.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged by remote attackers to perform denial of service attacks against web applications that utilize PHP's Fileinfo extension. When an attacker successfully exploits this vulnerability through a crafted CDF file, the target application crashes and becomes unavailable to legitimate users, potentially causing significant business disruption. This attack vector is particularly dangerous in web environments where PHP processes user-uploaded files or files from external sources, as it allows attackers to compromise service availability without requiring elevated privileges or complex exploitation techniques. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how improper input validation can lead to system instability.
Organizations affected by this vulnerability should immediately implement patches to upgrade their PHP installations to versions 5.4.30 or 5.5.14, which contain the necessary fixes for the sector-count validation issue. Additionally, administrators should consider implementing file type validation and sanitization measures to prevent processing of potentially malicious CDF files, particularly in environments where user uploads are permitted. The mitigation strategy should include monitoring for unusual application crashes or service disruptions that might indicate exploitation attempts, as well as implementing proper input validation controls at multiple layers of the application stack. Security teams should also consider deploying intrusion detection systems that can identify attempts to upload or process malformed CDF files, as this vulnerability can be effectively exploited through web-based attack vectors without requiring direct system access.