CVE-2014-7945 in Chrome
Summary
by MITRE
OpenJPEG before r2908, as used in PDFium in Google Chrome before 40.0.2214.91, allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted PDF document, related to j2k.c, jp2.c, and t2.c.
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Analysis
by VulDB Data Team • 12/11/2024
The vulnerability identified as CVE-2014-7945 represents a critical out-of-bounds read flaw within the OpenJPEG library implementation that was integrated into Google Chrome's PDFium component. This security weakness affected versions of Chrome prior to 40.0.2214.91 and stemmed from insufficient input validation within the JPEG 2000 image processing code. The vulnerability specifically manifested in the j2k.c, jp2.c, and t2.c source files, which handle core JPEG 2000 decoding operations. Attackers could exploit this weakness by crafting malicious PDF documents containing specially formatted JPEG 2000 images that would trigger memory access violations when processed by the vulnerable PDFium rendering engine.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where programs access memory locations beyond the intended buffer boundaries. This flaw operates at the intersection of image processing and memory safety, where the JPEG 2000 decoder fails to properly validate image dimensions and data structures before attempting to read from memory regions. The attack vector involves remote code execution through web-based PDF documents, making it particularly dangerous in enterprise environments where users frequently encounter untrusted PDF content. When the PDFium component processes a malformed JPEG 2000 image embedded within a PDF, the decoder's insufficient bounds checking causes it to read memory beyond allocated buffers, potentially leading to application crashes or more severe memory corruption scenarios.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a potential pathway for more sophisticated attacks within the attack chain defined by MITRE ATT&CK framework. While the immediate effect was a denial of service condition causing browser crashes, the underlying memory safety issue could theoretically be leveraged to execute arbitrary code on affected systems. This makes the vulnerability particularly concerning in targeted attack scenarios where adversaries might combine this weakness with other exploits to achieve persistent access. The vulnerability's presence in PDFium also indicates a broader concern with how web browsers handle embedded image formats, as PDF documents often contain multiple embedded objects including images, fonts, and other media that could be exploited. The remote nature of the attack means that users could be compromised simply by opening a malicious PDF document, making it a significant threat in phishing campaigns and exploit delivery mechanisms.
Mitigation strategies for CVE-2014-7945 primarily involve updating to patched versions of Google Chrome where the vulnerability has been addressed through improved input validation and bounds checking within the OpenJPEG library integration. Organizations should ensure that all affected systems are updated to Chrome version 40.0.2214.91 or later, which includes the necessary patches to prevent the out-of-bounds read conditions. Network administrators should also consider implementing PDF scanning and filtering mechanisms at network perimeters to detect and block potentially malicious PDF documents containing malformed JPEG 2000 images. Additionally, browser security configurations should be reviewed to ensure that PDF rendering is properly sandboxed and that users are not automatically opening PDF content without proper security checks. The vulnerability serves as a reminder of the importance of keeping third-party libraries updated and maintaining comprehensive patch management programs, particularly for components that handle untrusted data processing such as image decoders and document rendering engines.