Security Bulletin MS02-041: Unchecked Buffer in Content Management Server Could Enable Server Compromise (Q326075)

2002-08-08T00:00:00
ID SECURITYVULNS:DOC:3331
Type securityvulns
Reporter Securityvulns
Modified 2002-08-08T00:00:00

Description


Title: Unchecked Buffer in Content Management Server Could Enable Server Compromise (Q326075) Date: 07 August 2002 Software: Microsoft Content Management Server Impact: Three vulnerabilities, the most serious of which could enable an attacker to run code of an attackers choice. Max Risk: Critical Bulletin: MS02-041

Microsoft encourages customers to review the Security Bulletin at: http://www.microsoft.com/technet/security/bulletin/MS02-041.asp .


Issue:

Microsoft Content Management Server (MCMS) 2001 is a .Net Enterprise Server product that simplifies developing and managing e-business web sites. Microsoft has learned of three security vulnerabilities affecting it:

  • A buffer overrun in a low-level function that performs user authentication. At least one web page included with MCMS 2001 passes inputs directly to the function, thereby potentially providing a way for an attacker to overrun the buffer. The result of exploiting the vulnerability would be to either cause MCMS to fail, or run code in the context of the MCMS service (which runs as Local System).

  • A vulnerability resulting from the confluence of two flaws affecting a function that allows files to be uploaded to the server. The first flaw lies in how the function authenticates requests, and would allow any user to submit an upload request. The second results because it is possible to override the upload location; where the function should upload files to a folder that only privileged users can access, it can be overridden to upload it to a temporary folder that does allow unprivileged users to call it. By exploiting the two flaws in tandem, an attacker could upload an .ASP or other file to the server, in a location from which it could be executed.

  • A SQL injection vulnerability affecting a function that services requests for image files and other resources. Exploiting the vulnerability could enable an attacker to run SQL commands on the server, which would not only allow data in the MCMS database to be added, changed or deleted, but also would enable the attacker to run operating system commands on the server.

Mitigating Factors:

Buffer Overrun in MCMS Authentication Operation:

  • The scope of the vulnerability could be significantly reduced if the URLScan tool were deployed on the server. It is likely that in this case, the vulnerability could only be used for denial of service attacks.

Program Execution via MCMS Authoring Function: - Exploiting the vulnerability would not grant the attacker administrative privileges on the server. Instead, the attacker's code would execute in the security context of the Web Application Manager (the IWAM_computername account), which has similar privileges to those of an interactively logged-on user.

SQL Injection via MCMS Resource Request: - Exploiting the vulnerability would not grant the attacker administrative privileges on the server. Instead, any operating system commands would be levied in the security context of the SQL Server 2000 service, which by default has only Domain User privileges.

Risk Rating:

  • Internet systems: Critical
  • Intranet systems: Critical
  • Client systems: None

Patch Availability:

  • A patch is available to fix this vulnerability. Please read the Security Bulletin at http://www.microsoft.com/technet/security/bulletin/ms02-041.asp for information on obtaining this patch.

Acknowledgment:

  • Joao Gouveia (tharbad@kaotik.org)

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