Editing JavaScript (section)

=== Browser and plugin coding errors ===
{{Further|Buffer overflow}}
JavaScript provides an interface to a wide range of browser capabilities, some of which may have flaws such as [[buffer overflow]]s. These flaws can allow attackers to write scripts that would run any code they wish on the user's system. This code is not by any means limited to another JavaScript application. For example, a buffer overrun exploit can allow an attacker to gain access to the operating system's [[API]] with superuser privileges.

These flaws have affected major browsers including Firefox,<ref>Mozilla Corporation, [https://www.mozilla.org/security/announce/2006/mfsa2006-38.html Buffer overflow in crypto.signText()] {{Webarchive|url=https://web.archive.org/web/20140604014705/https://www.mozilla.org/security/announce/2006/mfsa2006-38.html |date=2014-06-04 }}</ref> Internet Explorer,<ref>{{cite web|last1=Festa |first1=Paul |title=Buffer-overflow bug in IE |url=https://news.com.com/2100-1001-214620.html |archive-url=https://web.archive.org/web/20021225190522/https://news.com.com/2100-1001-214620.html |url-status=dead |archive-date=December 25, 2002 |website=[[CNET]] |date=August 19, 1998 }}</ref> and Safari.<ref>SecurityTracker.com, [https://securitytracker.com/alerts/2006/Mar/1015713.html Apple Safari JavaScript Buffer Overflow Lets Remote Users Execute Arbitrary Code and HTTP Redirect Bug Lets Remote Users Access Files] {{Webarchive|url=https://web.archive.org/web/20100218102849/https://securitytracker.com/alerts/2006/Mar/1015713.html |date=2010-02-18 }}</ref>

Plugins, such as video players, [[Adobe Flash#Flash client security|Adobe Flash]], and the wide range of [[ActiveX]] controls enabled by default in Microsoft Internet Explorer, may also have flaws exploitable via JavaScript (such flaws have been exploited in the past).<ref>SecurityFocus, [https://www.securityfocus.com/bid/19030/info Microsoft WebViewFolderIcon ActiveX Control Buffer Overflow Vulnerability] {{Webarchive|url=https://web.archive.org/web/20111011091819/http://www.securityfocus.com/bid/19030/info |date=2011-10-11 }}</ref><ref>Fusion Authority, [https://www.fusionauthority.com/security/3234-macromedia-flash-activex-buffer-overflow.htm Macromedia Flash ActiveX Buffer Overflow] {{webarchive|url=https://web.archive.org/web/20110813160055/https://www.fusionauthority.com/security/3234-macromedia-flash-activex-buffer-overflow.htm |date=August 13, 2011 }}</ref>

In Windows Vista, Microsoft has attempted to contain the risks of bugs such as buffer overflows by running the Internet Explorer process with limited privileges.<ref>{{cite web |url=https://blogs.msdn.com/ie/archive/2006/02/09/528963.aspx |title=Protected Mode in Vista IE7 – IEBlog |website=Blogs.msdn.com |date=February 9, 2006 |access-date=February 24, 2017 |archive-date=January 23, 2010 |archive-url=https://web.archive.org/web/20100123103719/https://blogs.msdn.com/ie/archive/2006/02/09/528963.aspx |url-status=live }}</ref> [[Google Chrome]] similarly confines its page renderers to their own "[[Sandbox (computer security)|sandbox]]".