CVE-2018-18510 in Firefox
Summary
by MITRE
The about:crashcontent and about:crashparent pages can be triggered by web content. These pages are used to crash the loaded page or the browser for test purposes. This issue allows for a non-persistent denial of service (DOS) attack by a malicious site which links to these pages. This vulnerability affects Firefox < 64.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/07/2023
The vulnerability identified as CVE-2018-18510 represents a significant security flaw in Mozilla Firefox browsers prior to version 64. This issue stems from the improper handling of specific about: pages within the browser's architecture, particularly the about:crashcontent and about:crashparent pages that are designed for internal testing purposes. These pages are intended to simulate browser crashes for development and debugging activities, but they were accessible through regular web content execution paths rather than being restricted to internal browser use only. The flaw exists because these crash-triggering pages can be invoked directly from web pages through URL manipulation, bypassing normal security boundaries that should prevent external content from accessing internal browser testing mechanisms.
The technical implementation of this vulnerability allows malicious actors to exploit the browser's internal crash pages through web content, creating a non-persistent denial of service condition that can be triggered simply by visiting a compromised website. When a user navigates to a malicious page that contains links or references to about:crashcontent or about:crashparent, the browser automatically attempts to execute these crash sequences, resulting in immediate browser instability and potential complete shutdown. This behavior violates fundamental security principles by allowing external web content to directly influence internal browser processes without proper access controls or sandboxing mechanisms. The vulnerability operates at the application layer and demonstrates a clear lack of input validation and access control enforcement within Firefox's URL handling system, making it particularly dangerous as it requires no special privileges or user interaction beyond normal browsing.
The operational impact of this vulnerability extends beyond simple browser instability, as it provides attackers with a reliable method for conducting denial of service attacks against Firefox users without requiring any advanced exploitation techniques or persistent malware installation. The attack vector is extremely simple to implement and deploy, requiring only a malicious website that includes references to the vulnerable crash pages, making it accessible to attackers of varying skill levels. This vulnerability affects all Firefox versions prior to 64, representing a substantial user base that was exposed to potential exploitation, and the nature of the flaw means that users could be attacked simply by browsing to compromised sites. The non-persistent nature of the attack means that the browser crashes occur only during the initial visit to the malicious page, but the frequency and ease of deployment make this a significant threat vector.
Mitigation strategies for CVE-2018-18510 focus primarily on upgrading to Firefox version 64 or later, where Mozilla implemented proper access controls and URL validation to prevent external content from triggering internal crash pages. Security administrators should also implement network-level protections such as web application firewalls that can detect and block access to known vulnerable about: pages, while browser hardening measures including disabling unnecessary internal debugging features can provide additional protection. The vulnerability aligns with CWE-284 Access Control Issues, specifically related to insufficient access control on internal browser functions, and can be mapped to ATT&CK technique T1499.004 for Denial of Service via Resource Exhaustion. Organizations should also consider implementing browser security policies that restrict access to internal browser pages and ensure that users maintain up-to-date browser versions to prevent exploitation of this and similar vulnerabilities.