CVE-2017-1000122 in WebKit
Summary
by MITRE
The UNIX IPC layer in WebKit, including WebKitGTK+ prior to 2.16.3, does not properly validate certain message metadata, allowing a compromised secondary process to cause a denial of service (release assertion) of the UI process. This vulnerability does not affect Apple products.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-1000122 resides within the UNIX Inter-Process Communication (IPC) layer of WebKit implementations, specifically affecting WebKitGTK+ versions prior to 2.16.3. This flaw represents a critical security issue within the browser engine architecture that governs how different processes communicate and share resources within web browsing environments. The vulnerability operates at the fundamental level of process isolation and resource management, where the IPC mechanisms fail to properly validate message metadata received from secondary processes. This design oversight creates a pathway for malicious actors to exploit the system's communication protocols and manipulate process behavior in unintended ways.
The technical exploitation of this vulnerability occurs when a compromised secondary process attempts to send specially crafted messages through the UNIX IPC mechanisms to the UI process. The flaw lies in the insufficient validation of message metadata, which allows an attacker to craft messages that trigger unexpected behavior in the UI process. When the UI process receives these malformed messages, it fails to properly handle the invalid metadata and subsequently releases assertions that should maintain system stability and process integrity. This assertion release results in a denial of service condition that effectively crashes or destabilizes the UI process, rendering the browser interface non-functional and disrupting user experience.
From an operational impact perspective, this vulnerability creates significant security implications for systems utilizing WebKitGTK+ implementations, as it enables a compromised process to indirectly affect the core user interface functionality. The vulnerability does not impact Apple products, indicating that the issue is specific to the open-source WebKitGTK+ implementation rather than Apple's proprietary WebKit variant. This distinction is crucial for system administrators and security professionals who must differentiate between affected and unaffected platforms. The denial of service condition can be exploited repeatedly, potentially leading to persistent disruption of web browsing services and creating opportunities for more sophisticated attacks that leverage the instability caused by process crashes.
The vulnerability maps directly to CWE-248, which addresses "Uncaught Exception" in software systems, and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript" in contexts where the IPC layer is manipulated through scripting environments. The flaw demonstrates a classic case of insufficient input validation and improper error handling within system-level communication protocols, where the absence of proper metadata validation creates a pathway for privilege escalation through process manipulation. Security practitioners should note that this vulnerability represents a process isolation failure that could potentially be leveraged in conjunction with other exploits to achieve broader system compromise, though the direct impact is limited to denial of service conditions.
Mitigation strategies for CVE-2017-1000122 focus primarily on updating to WebKitGTK+ version 2.16.3 or later, which includes patches that properly validate message metadata within the IPC layer. Organizations should also implement monitoring for abnormal process behavior and IPC communication patterns that might indicate exploitation attempts. Additional defensive measures include deploying process isolation mechanisms and restricting secondary process capabilities to minimize the impact of compromised processes. System administrators should conduct comprehensive vulnerability assessments to identify all affected WebKitGTK+ implementations and prioritize patch deployment according to risk assessment criteria. The vulnerability serves as a reminder of the critical importance of proper input validation and error handling in system-level components, particularly those governing inter-process communication and resource management within browser engines.