CVE-2014-4378 in Mac OS X
Summary
by MITRE
CoreGraphics in Apple iOS before 8 and Apple TV before 7 allows remote attackers to obtain sensitive information or cause a denial of service (out-of-bounds read and application crash) via a crafted PDF document.
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Analysis
by VulDB Data Team • 02/20/2022
The vulnerability identified as CVE-2014-4378 represents a critical security flaw within Apple's CoreGraphics framework that affected iOS versions prior to 8.0 and Apple TV versions prior to 7.0. This vulnerability resides in the PDF rendering capabilities of these operating systems, specifically exposing a flaw in how the CoreGraphics component processes malformed PDF documents. The issue manifests as an out-of-bounds read condition that can be triggered when the system attempts to parse specially crafted PDF files, leading to unpredictable behavior and potential system instability.
The technical nature of this vulnerability stems from insufficient input validation within the CoreGraphics rendering engine. When processing PDF documents, the system fails to properly validate array indices and memory boundaries during the parsing of PDF objects, particularly those related to graphics and font handling. This flaw allows an attacker to construct a malicious PDF document that contains malformed data structures which, when opened by a vulnerable system, causes the CoreGraphics framework to attempt reading memory locations beyond the allocated bounds. The vulnerability is classified under CWE-129 as an insufficient validation of array indices, which directly enables out-of-bounds memory access.
From an operational perspective, this vulnerability presents significant risks to affected systems as it can be exploited remotely through malicious PDF files delivered via email, web browsing, or file sharing channels. The impact of exploitation includes both information disclosure and denial of service conditions, making it particularly dangerous for enterprise environments where users may inadvertently open compromised documents. An attacker could potentially extract sensitive information from memory locations or cause application crashes that lead to system instability, effectively creating a persistent denial of service condition for the affected device.
The attack surface for this vulnerability extends across multiple user interaction points including web browsers, email clients, and document viewers that rely on CoreGraphics for PDF rendering. The remote exploitation capability means that users need not be directly targeted, as malicious PDF files could be distributed through various channels including compromised websites, social engineering campaigns, or malicious email attachments. The vulnerability's impact is particularly concerning given that PDF documents are commonly used in business environments and are often automatically opened by default applications, increasing the probability of successful exploitation.
Organizations and individual users affected by this vulnerability should immediately implement mitigation strategies including updating to the latest available versions of iOS and Apple TV operating systems where the vulnerability has been patched. System administrators should also consider implementing PDF scanning and filtering solutions at network boundaries to prevent potentially malicious documents from reaching end-user devices. Additionally, user education programs should emphasize the importance of avoiding opening PDF files from untrusted sources and maintaining current software versions to protect against known vulnerabilities. The remediation process should also include verifying that all PDF handling applications are updated and that automatic PDF opening features are disabled where possible to reduce exposure windows.