The protocolIs function in platform/KURLGoogle.cpp in WebCore in WebKit before r55822, as used in Google Chrome before 4.1.249.1036 and Flock Browser 3.x before 3.0.0.4112, does not properly handle whitespace at the beginning of a URL, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a crafted javascript: URL, as demonstrated by a \x00javascript:alert sequence.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14067
https://bugs.webkit.org/show_bug.cgi?id=35948
http://www.vupen.com/english/advisories/2011/0212
http://src.chromium.org/viewvc/chrome?view=rev&revision=41244
http://secunia.com/advisories/43068
http://lists.opensuse.org/opensuse-security-announce/2011-01/msg00006.html
http://googlechromereleases.blogspot.com/2010/03/stable-channel-update.html