Microsoft IIS ISAPI HTR chunked encoding heap buffer overflow
| iis-htr-chunked-encoding-bo (9327) |  High Risk |
Description:
Microsoft Internet Information Server (IIS) is vulnerable to a buffer overflow in the function that enables the chunked encoding data transfer mechanism, which is part of the ISAPI (Internet Services Application Programming Interface) extension that implements HTR functionality. Chunked encoding is a process by which a client generates a variable sized "chunk" of data and notifies the Web server of the data's size before transferring it, so that the Web server can allocate a buffer of the correct size. By sending a specially-crafted "chunk" of data that causes the incorrect buffer size to be allocated, a remote attacker could overflow a buffer and execute arbitrary code on the system or cause the IIS service to fail.
Platforms Affected:
- Microsoft, IIS 4.0
- Microsoft, IIS 5.0
Remedy:
For vulnerability detection:
Enable the following checks in the ISS Protection Platform:
IisHtrChunkedEncodingBo
MS02-028
Enable the following checks in the ISS Protection Platform:
HTTP_IIS_HTR_Chunked_Overflow
Block or restrict the following in the ISS Protection Platform as appropriate to the environment:
Port 80
For Manual Protection:
Apply the appropriate patch for your system, as listed in Microsoft Security Bulletin MS03-018. See References.
Note: Microsoft originally provided a patch for this vulnerability in MS02-028, but it was superseded by the patch released with MS02-062, and then superseded by the patch released with MS03-018.
Consequences:
Gain Access
References:
- BugTraq Mailing List, Thu Jun 13 2002 - 14:32:45 CDT, VNA - .HTR HEAP OVERFLOW at http://archives.neohapsis.com/archives/bugtraq/2002-06/0114.html.
- CIAC Information Bulletin M-089, MS Heap Overrun in HTR Chunked Encoding Vulnerability at http://www.ciac.org/ciac/bulletins/m-089.shtml.
- eEye Digital Security Advisory AD20020612, Windows 2000 and NT4 IIS .HTR Remote Buffer Overflow at http://www.eeye.com/html/Research/Advisories/AD20020612.html.
- Internet Security Systems Security Alert #120, Heap Overflow in IIS HTR Chunked Encoding at http://www.iss.net/xforce/alerts/id/advise120.
- Microsoft Security Bulletin MS02-028, Heap Overrun in HTR Chunked Encoding Could Enable Web Server Compromise (Q321599) at http://www.microsoft.com/technet/security/bulletin/ms02-028.mspx.
- Microsoft Security Bulletin MS02-062, Cumulative Patch for Internet Information Service (Q327696) at http://www.microsoft.com/technet/security/Bulletin/MS02-062.mspx.
- Microsoft Security Bulletin MS03-018, Cumulative Patch for Internet Information Service (811114) at http://www.microsoft.com/technet/security/bulletin/ms03-018.mspx.
- BID-4855: Microsoft IIS HTR Chunked Encoding Transfer Heap Overflow Vulnerability
- CVE-2002-0364: Buffer overflow in the chunked encoding transfer mechanism in IIS 4.0 and 5.0 allows attackers to execute arbitrary code via the processing of HTR request sessions, aka Heap Overrun in HTR Chunked Encoding Could Enable Web Server Compromise.
- US-CERT VU#313819: Microsoft Internet Information Server (IIS) contains remote buffer overflow in chunked encoding data transfer mechanism for HTR
Reported:
May 27, 2002
The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.
For corrections or additions please email xforce@iss.net