CVE-2010-1986 in Firefox
Summary
by MITRE
Mozilla Firefox 3.6.3 on Windows XP SP3 allows remote attackers to cause a denial of service (memory consumption and application crash) via JavaScript code that creates multiple arrays containing elements with long string values, and then appends long strings to the content of a P element, related to the gfxWindowsFontGroup::MakeTextRun function in xul.dll, a different vulnerability than CVE-2009-1571.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/05/2019
The vulnerability identified as CVE-2010-1986 represents a significant denial of service flaw affecting Mozilla Firefox version 3.6.3 running on Windows XP SP3 systems. This weakness stems from improper memory management within the browser's rendering engine, specifically within the gfxWindowsFontGroup::MakeTextRun function located in the xul.dll module. The vulnerability operates through a sophisticated exploitation technique that leverages JavaScript code to manipulate memory allocation patterns in ways that ultimately overwhelm system resources and cause application instability.
The technical mechanism behind this vulnerability involves the creation of multiple JavaScript arrays containing elements with exceptionally long string values, followed by the appending of these lengthy strings to the content of paragraph elements. This sequence of operations triggers a cascade of memory allocation requests that the gfxWindowsFontGroup::MakeTextRun function cannot properly handle. The function's inability to efficiently manage memory when processing these specific string operations leads to excessive memory consumption patterns that eventually result in application crashes and complete denial of service conditions. This flaw demonstrates a classic buffer overflow and memory management issue that occurs during text rendering operations on Windows systems.
The operational impact of CVE-2010-1986 extends beyond simple application instability, as it provides attackers with a reliable method for disrupting user sessions and potentially affecting system availability. When exploited, this vulnerability can cause Firefox to consume excessive memory resources, leading to system slowdowns or complete application termination. The vulnerability is particularly concerning in environments where users may be browsing untrusted websites or receiving malicious content through email attachments, as the exploitation can occur without user interaction beyond visiting a compromised webpage. The denial of service condition affects not only individual users but also broader network availability, especially in enterprise environments where multiple users may be simultaneously affected by a single malicious page.
Mitigation strategies for this vulnerability should focus on immediate browser updates and system hardening measures. Users should upgrade to Firefox versions that contain patches addressing this specific memory management issue, as the vulnerability was resolved through code modifications that improved memory allocation handling within the gfxWindowsFontGroup::MakeTextRun function. System administrators should implement browser security policies that restrict JavaScript execution on untrusted sites and consider deploying web application firewalls that can detect and block malicious JavaScript patterns associated with this vulnerability. Additionally, organizations should maintain regular patch management procedures to ensure all systems receive timely security updates, as this vulnerability represents a known weakness that was addressed through software patches rather than requiring complex workarounds. This issue aligns with CWE-129, which covers improper validation of array indices, and can be categorized under ATT&CK technique T1499.004 for network denial of service attacks, emphasizing the importance of proper input validation and memory management in browser security architectures.