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Insecure Library Loading

Secunia Advisory SA40412

Microsoft Internet Information Services Basic Authentication Security Bypass

Secunia Advisory

SA40412

Release Date

2010-07-02

Last Update

2010-09-14

Popularity

6,479 views

Comments

4 comments

Criticality level

Moderately critical

Impact

Security Bypass

Where

From remote

Authentication level

Available in Customer Area

Report reliability

Available in Customer Area

Solution Status

Vendor Patch

Systems affected

Available in Customer Area

Approve distribution

Available in Customer Area

Remediation status

Secunia CSI, Secunia PSI

Automated scanning

Secunia CSI, Secunia PSI

Software:

Microsoft Internet Information Services (IIS) 5.x

Secunia CVSS Score

Available in Customer Area

CVE Reference(s)

CVE-2010-2731 CVSS available in Customer Area

Description

Soroush Dalili has discovered a vulnerability in Microsoft Internet Information Services, which can be exploited by malicious people to bypass certain security restrictions.

The vulnerability is caused due to an error in the handling of basic authentication for directories. This can be exploited to bypass authentication and access e.g. protected directories by appending the NTFS stream name and stream type (":$i30:$INDEX_ALLOCATION") to the directory name within a request.

Solution
Apply patch.
Further details available in Customer Area

Provided and/or discovered by
Soroush Dalili

Changelog
Further details available in Customer Area

Original Advisory
MS10-065 (KB2267960, KB2290570):
http://www.microsoft.com/technet/security/bulletin/ms10-065.mspx

Soroush Dalili:
http://soroush.secproject.com/blog/2010/07/iis5-1-directory-authentication-bypass-by-using-i30index_allocation/

Deep Links
Links available in Customer Area

Do you have additional information related to this advisory?

Please provide information about patches, mitigating factors, new versions, exploits, faulty patches, links, and other relevant data by posting comments to this Advisory. You can also send this information to vuln@secunia.com

Subject: Microsoft Internet Information Services Basic Authentication Security Bypass

User

Message

RichardD

RE: Microsoft Internet Information Services Basic Authentication Security Bypass

5th Jul, 2010 14:29

Score: 7
Posts: 5
User Since: 4th Mar 2010
System Score: N/A
Location: UK
Last edited on 5th Jul, 2010 14:29

Looks like URLScan blocks this vulnerability by default. I've just tried the URL against one of our old Windows 2000 servers, and it gives me a 404 error.

Was this reply relevant?

-0

shinnai

RE: Microsoft Internet Information Services Basic Authentication Security Bypass

7th Jul, 2010 12:05

Score: 7
Posts: 3
User Since: 11th Jan 2008
System Score: N/A
Location: IT
Last edited on 7th Jul, 2010 12:05

I can confirm what RichardD said. I've followed step by step the paper written by Soroush Dalili and I just get a 404 error. Where am I wrong?

Was this reply relevant?

-1

taffy078

RE: Microsoft Internet Information Services Basic Authentication Security Bypass

7th Jul, 2010 14:12

Score: 347
Posts: 1,019
User Since: 26th Feb 2009
System Score: 100%
Location: UK

Hi Shinnai, and welcome to this forum..

Being new, you won't be aware that this section, “ Vulnerabilities”, is used by the Secunia team to announce problems.

You will have more chance of getting help, more quickly, if you post a new thread in one of the other sections (see the list on the left).

If you do, it will help us help you if you give details of your system etc - as I have done, below.

Best wishes.

--
taffy078, West Yorkshire, UK

Compaq Presario (OEM) 32 bit / AMD Athlon / 2 GB RAM
XP Home - SP3/ IE8/ Norton IS / Secunia PSI v2.0.0.4003

Was this reply relevant?

-1

shinnai

RE: Microsoft Internet Information Services Basic Authentication Security Bypass

7th Jul, 2010 17:23

Score: 7
Posts: 3
User Since: 11th Jan 2008
System Score: N/A
Location: IT
Last edited on 7th Jul, 2010 17:23

taffy078 thanks a lot and sorry for my mistake

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-0

Secunia

Secunia Advisory SA40412

Microsoft Internet Information Services Basic Authentication Security Bypass

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