Re: Apache goes berserk

From: Tobias Rosenstock (jeedi@Crew-KG.DE)
Date: Thu Jun 27 2002 - 14:09:25 PDT

  • Next message: RUSSELL T. LEWIS: "win2k server issue"

    Hi,
    
    On Wed, 26 Jun 2002, Brett Glass wrote:
    
    > This evening, I returned from dinner to find that my Apache 2.0.39 Web
    > server, running on FreeBSD, was completely unresponsive. A "ps" command
    > revealed that the server had spawned dozens of child processes. And the
    > error log had filled up with messages that looked like this:
    >
    > [Wed Jun 26 21:28:36 2002] [warn] child process 164 still did not exit,
    > sending a SIGTERM
    [...]
    
    > ...and many more similar messages. These were followed by a continuous
    > stream of messages like the following:
    >
    > httpd in free(): warning: page is already free
    [...]
    
    > It doesn't LOOK as if anyone broke in, but the fact that the Web server
    > was tied up in knots until I shut it down and restarted it is disturbing.
    > Anyone else seeing such activity?
    
    looks like your box is under fire from someone who tries to break in
    through the well-published apache chunked request vulnerability, probably
    even using apache-scalp.c, which was published on bugtraq last week.
    
    i noticed similar behavior of my apache 1.3.24 before updating to 1.3.26
    when scanning it in "brute-force" mode with the binary compiled from
    apache-scalp.c, apache 1.3.26, however, seems to ignore that kind of
    error, or at least not log it. while scanning this version, all i could
    see in the access log was "regular" loglines for a "GET / HTTP/1.1" and a
    casual http-error 200 (Bad Request) in the error log.
    
    also, i'm not experiencing any performance problems, even when "scalping"
    the server from a box that's connected to it via a 100mbit switch. maybe
    this is an apache-2.x-only problem.
    
    tobias.
    -- 
     NOC Hamster       - Security Guy      - Owner of one, root of many
     Tobias Rosenstock - jeedi@crew-kg.de  - jeediat_private  - mailat_private
     Wieske's Crew KG  - http://irz42.net  - http://www.crew-kg.de
     Humboldtstr. 51   - Lessingstr.       - 22083 Hamburg - Germany
    
    
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