Opera '%2F' URL Parsing Error Lets Remote Users Spoof Arbitrary URLs
SecurityTracker Alert ID: 1010481|
SecurityTracker URL: http://securitytracker.com/id/1010481
(Links to External Site)
Date: Jun 13 2004
Modification of system information|
Exploit Included: Yes |
A vulnerability was reported in the Opera web browser in the parsing of URLs containing the '%2F' character. A remote user can spoof arbitrary URLs.|
http-equiv reported that 'bitlance winter' discovered that a remote user can create a specially crafted HTML link that, when loaded by the target user, will cause an arbitrary web site to be loaded with a partially spoofed URL. The partially spoofed URL will contain the full URL but may also contain space or null characters that cause the portion of the URL containing the attacker's site to be pushed far enough to the right in the URL status bar so as to not be visible.
The web site can be loaded in the security domain of an arbitrary site.
A demonstration exploit link is provided:
<a href="http://www.microsoft.com%2F redir=www.e-gold.com">test</a>
It is reported that the attacker's exploit site must be configured to respond to HTTP queries regardless of what value is specified for the HTTP "Host:" header.
Brett Moore reported that the malicious URL does not need to include the 'redir' attribute.
A demonstration exploit example that uses an SSL-based exploit site is provided at:
A remote user can create HTML that, when loaded by the target user, will spoof an arbitrary site.|
No solution was available at the time of this entry.|
Vendor URL: www.opera.com/ (Links to External Site)
Input validation error, State error|
|Underlying OS: Windows (Any)|
Source Message Contents
Subject: [Full-Disclosure] COELACANTH: Phreak Phishing Expedition|
Thursday, June 10, 2004
The following was presented by 'bitlance winter' of Japan today:
<a href="http://www.microsoft.com%2F redir=www.e-
Quite inexplicable from these quarters. Perhaps someone with
server 'knowledge' can examine it.
It carries over the address into the address bar:
[screen shot: http://www.malware.com/gosh.png 72KB]
while redirecting to egold. The key being %2F without that it
fails. The big question is where is the 'redir' and why is it
only applicable [so far] to e-gold. Other sites don't work and e-
gold is running an old Microsoft-IIS/4.0.
credit: 'bitlance winter'
Full-Disclosure - We believe in it.