Vulnerability Note VU#601312

Lotus Domino vulnerable to DoS via crafted HTTP header requests

Original Release date: 12 Jul 2001 | Last revised: 17 Jul 2001


The Lotus Domino Web Server contains a flaw that could be exploited to cause a denial of service.


HTTP requests with uniquely crafted headers using "Accept", "Accept-Charset", "Accept-Encoding", "Accept-Language" or "Content-Type" are not freed properly. This means that submitting numerous requests for a document, such as root (/), with various accept fields (accept: a, accept: aa, accept: aaa, ...) will cause the server to run out of physical memory. The server will then display an error message similar to this one:

"HTTP Server: Could allocate 8036 bytes of memoryOut of memory in HTMemPoolAlloc (file htmpool.c, line 506).Program aborted."

One of two things will then happen:

1) Processes that required working threads such as Task Manager will cease to function and the Lotus Server, while continuing to run, will no longer answer requests on TCP port 80. Also, any occupied memory will not be released.


2) The Lotus Server process will crash, and will need to be restarted in order to regain functionality. The rest of the services, unrelated to the Lotus Server, on the host will continue to function normally.


The server will eventually run out of physical memory and a denial of service will result.


Upgrade to Notes/Domino 5.0.7 or later. See

An application layer filter may be able to detect and block unapproved requests.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
LotusAffected16 Oct 200012 Jul 2001
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



Our thanks to Defcom Labs, which published an advisory on this and other problems, available at

This document was written by Jason Rafail and is based on information obtained from a Defcom Labs Advisory.

Other Information

  • CVE IDs: Unknown
  • Date Public: 11 Apr 2001
  • Date First Published: 12 Jul 2001
  • Date Last Updated: 17 Jul 2001
  • Severity Metric: 9.98
  • Document Revision: 19


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