Multiple vulnerabilities have been reported in Microsoft SharePoint, which can be exploited by malicious users to conduct script insertion attacks and by malicious people to conduct cross-site scripting attacks.

1) Input passed via the URL is not properly sanitised within the SharePoint Calendar before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

2) Input passed to the SafeHTML function is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

3) Input passed to EditForm.aspx is not properly sanitised before being used. This can be exploited to insert arbitrary HTML and script code, which will be executed in a user's browser session in context of an affected site when the malicious data is being viewed.

4) Input passed via Contact details is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

5) Input passed via the URL is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.

NOTE: Additionally, a weakness exists when handling certain input and can be exploited to redirect a client to a malicious web site.

Solution
Apply patches.
Further details available to Secunia VIM customers

Provided and/or discovered by
4) Seeker Security.

The vendor credits:
1) Andrew Connell, Critical Path Training, LLC and David Feldman, Raytheon.
2) Adi Cohen, IBM Rational Application Security.
3) Pedro Jimenez, ITT.
5) Jim LaValley, LaValley Consulting, LLC.

Changelog
Further details available to Secunia VIM customers

Original Advisory
MS11-074 (KB2493987, KB2494001, KB2494007, KB2494022, KB2508964, KB2508965, KB2552998, KB2552999, KB2553001, KB2553002, KB2553003, KB2553005, KB2560885, KB2566449, KB2566450, KB2566456, KB2566954, KB2566958, KB2566960):
http://technet.microsoft.com/en-us/security/bulletin/ms11-074

Seeker Security:
http://www.seekersec.com/Advisories/SeekerAdvMS03.html
http://www.seekersec.com/Advisories/SeekerAdvMS04.html

Deep Links
Links available to Secunia VIM customers