CVE-2010-1392 in Safari
Summary
by MITRE
Use-after-free vulnerability in WebKit in Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via vectors related to HTML buttons and the first-letter CSS style.
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Analysis
by VulDB Data Team • 09/15/2021
The CVE-2010-1392 vulnerability represents a critical use-after-free flaw within the WebKit rendering engine that powers Apple Safari browsers across multiple operating systems. This vulnerability specifically affects Safari versions prior to 5.0 on Mac OS X 10.5 through 10.6 and Windows platforms, as well as versions before 4.1 on Mac OS X 10.4. The flaw occurs in the browser's handling of HTML elements combined with CSS styling properties, creating a dangerous condition where memory previously freed by the application is accessed again by malicious code. Such vulnerabilities fall under the CWE-416 category of Use After Free, which is classified as a serious memory corruption issue that can lead to arbitrary code execution or system instability. The vulnerability's exploitation pathway involves crafting malicious HTML content that triggers specific interactions between button elements and first-letter CSS styling properties, creating a scenario where the browser's memory management fails to properly track object lifecycles.
The technical implementation of this vulnerability exploits the browser's rendering engine's improper handling of CSS pseudo-elements, specifically targeting the first-letter styling feature when combined with interactive HTML button elements. When Safari processes web content containing these specific combinations, the WebKit engine creates a memory allocation for a button object and subsequently frees it during normal processing. However, the CSS first-letter styling directive maintains a reference to this freed memory location, creating a use-after-free condition. This flaw demonstrates the complexity of modern browser security where seemingly innocuous CSS properties can interact with DOM manipulation in unexpected ways. The vulnerability's impact extends beyond simple exploitation as it can be leveraged for both remote code execution and denial of service attacks, making it particularly dangerous for web-based threat actors. According to ATT&CK framework, this vulnerability maps to T1059.007 for Command and Scripting Interpreter and T1595.001 for Network Boundary Bridging, as it enables attackers to execute arbitrary code on victim systems through web-based delivery mechanisms.
The operational impact of CVE-2010-1392 extends across multiple platform configurations and affects a significant portion of Safari users during the affected time period. The vulnerability's cross-platform nature means that attackers could target users across different operating systems with a single exploit vector, increasing the potential attack surface. Organizations and individual users running affected Safari versions faced substantial risk as the vulnerability could be triggered through standard web browsing activities, including visiting compromised websites or opening malicious email attachments containing HTML content. The memory corruption aspect of this vulnerability makes it particularly challenging to detect and prevent through traditional security measures, as the exploitation occurs at the application level rather than network level. The flaw's ability to cause both arbitrary code execution and denial of service means that threat actors could choose their preferred attack method depending on their objectives, with code execution providing persistent access to compromised systems and denial of service offering a simple but effective disruption capability. Security professionals working with web application security would classify this vulnerability as high-risk due to its potential for remote code execution and the difficulty in patching systems that rely on older browser versions for legacy application compatibility. The vulnerability also highlights the importance of keeping browser software updated, as the issue was resolved through subsequent Safari releases that properly managed memory allocation and deallocation processes for CSS pseudo-elements.