CVE-2014-7944 in Chrome
Summary
by MITRE
The sycc422_to_rgb function in fxcodec/codec/fx_codec_jpx_opj.cpp in PDFium, as used in Google Chrome before 40.0.2214.91, does not properly handle odd values of image width, which allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted PDF document.
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Analysis
by VulDB Data Team • 12/11/2024
The vulnerability identified as CVE-2014-7944 resides within the PDFium library's handling of JPEG 2000 image decoding operations, specifically in the sycc422_to_rgb function located at fxcodec/codec/fx_codec_jpx_opj.cpp. This flaw affects Google Chrome versions prior to 40.0.2214.91 and represents a classic buffer over-read condition that can be exploited through maliciously crafted PDF documents. The vulnerability stems from inadequate input validation when processing image width parameters during the conversion of YUV 4:2:2 color space to RGB format, creating a scenario where the decoding process fails to properly account for odd width values that fall outside the expected parameter boundaries.
The technical implementation of this vulnerability occurs when PDFium processes JPEG 2000 images with odd width dimensions, causing the sycc422_to_rgb function to attempt memory accesses beyond the allocated buffer boundaries. This improper handling of image dimensions creates an out-of-bounds read condition that can be triggered by remote attackers through carefully constructed PDF files containing malformed JPEG 2000 image data. The flaw operates at the intersection of image processing and memory management, where the decoding algorithm fails to validate that width parameters remain within acceptable ranges before performing arithmetic operations that determine memory access patterns. This issue aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and demonstrates how improper boundary checking in image processing code can lead to memory corruption scenarios.
From an operational perspective, this vulnerability enables remote attackers to execute denial of service attacks against systems running affected versions of Google Chrome. The out-of-bounds read condition typically results in application crashes or unstable behavior rather than arbitrary code execution, though the impact can still be significant in environments where continuous availability is critical. The attack vector requires the victim to open a specially crafted PDF document, making this a client-side vulnerability that leverages social engineering techniques to deliver malicious payloads. The vulnerability's exploitation potential extends beyond simple denial of service as it can potentially be chained with other memory corruption issues to achieve more severe outcomes, particularly in browser environments where memory safety is paramount.
The mitigation strategy for CVE-2014-7944 involves updating to Google Chrome version 40.0.2214.91 or later, which includes patches that properly validate image width parameters before processing JPEG 2000 data. Organizations should prioritize patch management to address this vulnerability, as it represents a known security risk that can be exploited remotely without user interaction beyond opening a malicious document. Additional defensive measures include implementing content filtering solutions that can detect and block suspicious PDF files, configuring browser security settings to limit PDF processing capabilities, and maintaining awareness of the ATT&CK framework's T1203 technique related to exploitation of memory corruption vulnerabilities. The vulnerability serves as an example of how image processing libraries can introduce security risks when proper input validation and boundary checking are not implemented, emphasizing the importance of robust security practices in multimedia processing components.