Secunia Research: Opera 8 XMLHttpRequest Security Bypass

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                   Secunia Research 16/06/2005

            - Opera 8 XMLHttpRequest Security Bypass -

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Table of Contents

Affected Software....................................................1
Severity.............................................................2
Description of Vulnerability.........................................3
Solution.............................................................4
Time Table...........................................................5
Credits..............................................................6
References...........................................................7
About Secunia........................................................8
Verification.........................................................9

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1) Affected Software

Opera 8.0 Final Build 1095

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2) Severity

Rating: Moderately critical
Impact: Security Bypass
Where:  From remote

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3) Description of Vulnerability

Secunia Research has discovered a vulnerability in Opera, which can
be exploited by malicious people to steal content or to perform
actions on other web sites with the privileges of the user.

Normally, it should not be possible for the XMLHttpRequest object to
access resources from outside the domain of which the object was
opened. However, due to insufficient validation of server side
redirects, it is possible to circumvent this restriction.

The vulnerability has been confirmed in version 8.0.

Please note. This issue has prior been reported in Internet Explorer
by Jelmer, and later reported in Mozilla/Netscape by GreyMagic.

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4) Solution

Update to Opera 8.01
http://www.opera.com/download/

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5) Time Table

19/04/2005 - Vulnerability discovered and reported to vendor.
16/06/2005 - Public disclosure.

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6) Credits

Discovered by Jakob Balle, Secunia Research.

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7) References

The Common Vulnerabilities and Exposures (CVE) project has assigned 
candidate number CAN-2005-1475 for the vulnerability.

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8) About Secunia

Secunia collects, validates, assesses, and writes advisories regarding
all the latest software vulnerabilities disclosed to the public. These
advisories are gathered in a publicly available database at the
Secunia web site:

http://secunia.com/

Secunia offers services to our customers enabling them to receive all
relevant vulnerability information to their specific system
configuration.

Secunia offers a FREE mailing list called Secunia Security Advisories:

http://secunia.com/secunia_security_advisories/

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9) Verification

Please verify this advisory by visiting the Secunia web site:
http://secunia.com/secunia_research/2005-04/advisory/

Complete list of vulnerability reports released by Secunia Research:
http://secunia.com/secunia_research/

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