Microsoft Security Bulletin MS13-024 - Critical

Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors may be helpful in your situation:

• In a web-based attack scenario, an attacker could host a website that contains a webpage that is used to exploit this vulnerability. In addition, compromised websites and websites that accept or host user-provided content or advertisements could contain specially crafted content that could exploit this vulnerability. In all cases, however, an attacker would have no way to force users to visit these websites. Instead, an attacker would have to convince users to visit the website, typically by getting them to click a link in an email message or Instant Messenger message that takes users to the attacker's website.

Microsoft has not identified any workarounds for this vulnerability.

What is the scope of the vulnerability? 
This is an elevation of privilege vulnerability.

What causes the vulnerability? 
The vulnerability is caused when Microsoft SharePoint Server does not properly handle properly validate user input.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could read content that the attacker is not authorized to read, use the victim's identity to take actions on the SharePoint site on behalf of the victim, such as change permissions and delete content, and inject malicious content in the browser of the victim.

How could an attacker exploit the vulnerability? 
For this vulnerability to be exploited, an attacker must input a specially crafted URL to a system running an affected version of SharePoint Server.

What systems are primarily at risk from the vulnerability? 
Systems that are running an affected version of SharePoint Server are primarily at risk.

What does the update do? 
The update addresses the vulnerability by correcting the way that Microsoft SharePoint Server validates user input.

When this security bulletin was issued, had this vulnerability been publicly disclosed? 
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited? 
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.

Microsoft has not identified any mitigating factors for this vulnerability.

Microsoft has not identified any workarounds for this vulnerability.

What is the scope of the vulnerability? 
This is an elevation of privilege vulnerability.

What causes the vulnerability? 
The vulnerability is caused when Microsoft SharePoint Server does not properly handle malicious JavaScript elements contained within a specially crafted site content, allowing the script to be displayed back to the user's browser.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could read content that the attacker is not authorized to read, use the victim's identity to take actions on the SharePoint site on behalf of the victim, such as change permissions and delete content, and inject malicious content in the browser of the victim.

How could an attacker exploit the vulnerability? 
For this vulnerability to be exploited, a user must visit a specially crafted page usually only available to SharePoint administrators.

What systems are primarily at risk from the vulnerability? 
Systems where users connect to a SharePoint server, such as workstations or terminal servers, are primarily at risk.

What does the update do? 
The update addresses the vulnerability by correcting the way that Microsoft SharePoint Server validates user input.

When this security bulletin was issued, had this vulnerability been publicly disclosed? 
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited? 
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.

Microsoft has not identified any mitigating factors for this vulnerability.

Microsoft has not identified any workarounds for this vulnerability.

What is the scope of the vulnerability? 
This is an elevation of privilege vulnerability.

What causes the vulnerability? 
The vulnerability is caused when Microsoft SharePoint Server does not properly handle properly validate user input.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could read content that the attacker is not authorized to read, use the victim's identity to take actions on the SharePoint site on behalf of the victim, such as change permissions and delete content, and inject malicious content in the browser of the victim.

How could an attacker exploit the vulnerability? 
For this vulnerability to be exploited, an attacker must input a specially crafted URL to a system running an affected SharePoint Server.

What systems are primarily at risk from the vulnerability? 
Systems that are running an affected version of SharePoint Server are primarily at risk.

What does the update do? 
The update addresses the vulnerability by correcting the way that Microsoft SharePoint Server validates URLs.

When this security bulletin was issued, had this vulnerability been publicly disclosed? 
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited? 
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.

Microsoft has not identified any mitigating factors for this vulnerability.

Microsoft has not identified any workarounds for this vulnerability.

What is the scope of the vulnerability? 
This is a denial of service vulnerability.

What causes the vulnerability? 
The vulnerability is caused when Microsoft SharePoint does not properly handle properly validate user input.

What might an attacker use the vulnerability to do? 
An attacker who successfully exploited this vulnerability could cause the W3WP process on an affected version of SharePoint Server to terminate, causing the SharePoint site, and any other sites running under that process, to become unavailable until the process is restarted.

How could an attacker exploit the vulnerability? 
For this vulnerability to be exploited, an attacker must enter a specially crafted URL to a system running an affected version of SharePoint.

What systems are primarily at risk from the vulnerability? 
Systems that are running an affected version of SharePoint are primarily at risk.

What does the update do? 
The update addresses the vulnerability by correcting the way that Microsoft SharePoint Server validates URLs.

When this security bulletin was issued, had this vulnerability been publicly disclosed? 
No. Microsoft received information about this vulnerability through coordinated vulnerability disclosure.

When this security bulletin was issued, had Microsoft received any reports that this vulnerability was being exploited? 
No. Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers when this security bulletin was originally issued.

Reference Table

The following table contains the security update information for this software.

Reference Table

The following table contains the security update information for this software.