CVE-2010-1785 in Safari
Summary
by MITRE
WebKit in Apple Safari before 5.0.1 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1.1 on Mac OS X 10.4; and webkitgtk before 1.2.6; accesses uninitialized memory during processing of the (1) :first-letter and (2) :first-line pseudo-elements in an SVG text element, which allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted document.
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Analysis
by VulDB Data Team • 09/21/2021
The vulnerability identified as CVE-2010-1785 represents a critical memory safety issue within the WebKit rendering engine that powers Apple Safari and various other web browsers. This flaw specifically affects the processing of CSS pseudo-elements :first-letter and :first-line within SVG text elements, creating a pathway for remote code execution or denial of service attacks. The vulnerability impacts multiple operating systems including Mac OS X versions 10.4 through 10.6 and Windows platforms, with the affected versions being Safari 5.0.1 and earlier on Mac OS X 10.5 through 10.6, and Safari 4.1.1 and earlier on Mac OS X 10.4. Additionally, the webkitgtk library versions prior to 1.2.6 are also vulnerable to this issue.
The technical root cause of this vulnerability lies in the improper handling of uninitialized memory during the rendering process of SVG text elements with specific CSS pseudo-selectors. When WebKit encounters an SVG text element that utilizes the :first-letter or :first-line pseudo-elements, the engine fails to properly initialize memory locations before accessing them, leading to undefined behavior. This memory access pattern creates a potential exploitation vector where malicious actors can craft specially designed SVG documents that trigger memory corruption when processed by the vulnerable browser engine. The uninitialized memory access occurs during the CSS layout and rendering phases, specifically when the browser attempts to calculate and display the visual properties of text elements that utilize these pseudo-selectors.
From an operational perspective, this vulnerability poses significant security risks to users who browse the internet with affected browser versions. Remote attackers can exploit this flaw by delivering malicious web pages containing crafted SVG content that, when rendered by the vulnerable browser, causes the application to execute arbitrary code with the privileges of the user running the browser. Alternatively, the vulnerability can be leveraged to cause application crashes, leading to denial of service conditions that disrupt normal browsing operations. The impact extends beyond individual user sessions as this vulnerability affects a wide range of operating systems and browser versions, making it particularly dangerous for widespread exploitation. The vulnerability's classification aligns with CWE-457, which describes "Use of Uninitialized Variable" and is commonly associated with memory safety issues that can lead to arbitrary code execution.
The exploitation of this vulnerability typically involves crafting SVG documents that contain specific combinations of text elements and CSS pseudo-selectors that trigger the uninitialized memory access pattern. Attackers can deliver these malicious documents through various vectors including compromised websites, email attachments, or malicious web applications. The ATT&CK framework categorizes this type of vulnerability under software exploitation techniques, specifically targeting browser rendering engines and memory management functions. Security researchers have noted that the vulnerability's exploitation often requires user interaction, such as visiting a malicious website, but the potential for automated exploitation exists depending on the specific implementation details of the browser's rendering engine.
Organizations and users should immediately apply security patches released by Apple and other vendors to address this vulnerability. The recommended mitigation strategy involves updating Safari browsers to versions 5.0.1 or later on Mac OS X 10.5 through 10.6, and 4.1.1 or later on Mac OS X 10.4, while also updating webkitgtk libraries to version 1.2.6 or later. System administrators should also consider implementing browser security policies that restrict access to untrusted websites and maintain regular patch management procedures to address similar vulnerabilities. The vulnerability serves as a reminder of the critical importance of memory safety in browser engines and the need for comprehensive security testing of rendering components that handle complex web standards such as SVG and CSS pseudo-elements.