CVE-2010-2295 in Chrome
Summary
by MITRE
page/EventHandler.cpp in WebCore in WebKit in Google Chrome before 5.0.375.70 does not properly handle a change of the focused frame during the dispatching of keydown, which allows user-assisted remote attackers to redirect keystrokes via a crafted HTML document, aka rdar problem 7018610. NOTE: this might overlap CVE-2010-1422.
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Analysis
by VulDB Data Team • 09/16/2021
The vulnerability identified as CVE-2010-2295 represents a critical flaw in the WebKit rendering engine's handling of keyboard event propagation within Google Chrome browsers. This issue specifically affects versions prior to Chrome 5.0.375.70 and stems from improper management of focus changes during keydown event dispatching. The vulnerability operates at the core WebCore component level where the browser's HTML processing engine manages event handling and frame navigation. Attackers can exploit this weakness by crafting malicious HTML documents that manipulate the focused frame during keyboard event processing, creating an unexpected redirection of keystrokes to unintended targets.
The technical implementation of this vulnerability resides in the EventHandler.cpp file within WebCore's page handling subsystem. When a keydown event is dispatched, the system should maintain consistent focus context throughout the event processing lifecycle. However, the flaw allows for a scenario where a focus change occurs mid-event dispatch, causing the system to redirect subsequent keystrokes to the newly focused frame rather than the originally intended target. This behavior violates fundamental assumptions about event propagation consistency and creates a pathway for attackers to manipulate keyboard input routing. The vulnerability specifically impacts the browser's ability to maintain proper event context when frame boundaries are crossed during active keyboard input processing, creating a window where malicious code can intercept and redirect keystrokes.
From an operational perspective, this vulnerability enables attackers to perform sophisticated keystroke redirection attacks that can compromise user input security. The attack requires user interaction through visiting a malicious webpage, making it a user-assisted remote attack vector. Once exploited, the vulnerability could allow attackers to redirect sensitive input such as passwords, form data, or navigation commands to unintended targets within the browser interface. The impact extends beyond simple keystroke redirection to potentially enable more complex attacks including form hijacking, credential theft, and session manipulation. Security researchers have noted that this vulnerability could be particularly dangerous in environments where users interact with multiple frames or iframes, as the attack surface expands with the complexity of the page structure.
The mitigation strategies for CVE-2010-2295 involve updating to Chrome version 5.0.375.70 or later, which includes the necessary patches to properly handle focus changes during event dispatching. Browser vendors should implement robust event context management that prevents focus transitions from altering event routing during active processing. Additionally, defensive programming practices should ensure that event handlers maintain consistent focus state throughout their execution lifecycle. This vulnerability aligns with CWE-691, which addresses inadequate protection against uncontrolled recursion or event handling, and relates to ATT&CK technique T1056.001 for input injection. Organizations should conduct comprehensive security assessments of their browser environments and ensure timely patch deployment to prevent exploitation. The vulnerability demonstrates the critical importance of maintaining proper event context management in complex browser environments where multiple frames and focus states interact dynamically during user interaction.