EGP Detection

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

# See RFC 827 & RFC 888

include('deprecated_nasl_level.inc');
include("compat.inc");

if (description)
{
  script_id(11908);
  script_version("1.19");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");

  script_name(english:"EGP Detection");

  script_set_attribute(attribute:"synopsis", value:
"The remote IP stack answers to an obsolete protocol.");
  script_set_attribute(attribute:"description", value:
"The remote host is running EGP, an obsolete routing protocol. 

If possible, this IP protocol should be disabled.");
  script_set_attribute(attribute:"solution", value:
"If this protocol is not needed, disable it or filter incoming traffic
going to IP protocol #8.");
  script_set_attribute(attribute:"risk_factor", value:"None");

  script_set_attribute(attribute:"plugin_publication_date", value:"2003/10/25");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"asset_inventory", value:"True");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Service detection");

  script_copyright(english:"This script is Copyright (C) 2003-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_require_keys("Settings/ThoroughTests");

  exit(0);
}


##include("dump.inc");
include('global_settings.inc');
include("network_func.inc");
if ( TARGET_IS_IPV6 ) exit(0);
if (islocalhost() || ! thorough_tests) exit(0);

s = compat::this_host();
v = eregmatch(pattern: "^([0-9]+)\.([0-9]+)\.([0-9]+)\.([0-9])+$", string: s);
if (isnull(v)) exit(0);
for (i = 1; i <=4; i++) a[i] = int(v[i]);

a1 = rand() % 256; a2 = rand() % 256;
s1 = rand() % 256; s2 = rand() % 256;

r = raw_string(	2,	# EGP version
		3,	# Type
		0,	# Code = Neighbor Acquisition Request
		0,	# Info (not used here)
		0, 0,	# checksum
		a1, a2,	# Autonomous system
		s1, s2,	# Identification
		0, 30,	# NR Hello Interval
		0, 120	# NR Poll Interval
	);

ck = ip_checksum(data: r);
r2 = insstr(r, ck, 4, 5);

egp = forge_ip_packet(ip_v: 4, ip_hl: 5, ip_tos: 0, ip_p: 8, ip_ttl: 64,
			ip_off: 0, ip_src: compat::this_host(),	data: r2);

f = "ip proto 8 and src " + get_host_ip();
for ( i = 0 ; i < 3 ; i ++ )
{
 r = send_packet(egp, pcap_active: TRUE, pcap_filter: f, pcap_timeout:1);
 if ( r ) break;
}
if ( r == NULL ) exit(0);

hl = ord(r[0]) & 0xF; hl *= 4;
egp = substr(r, hl);
if (ord(egp[0]) == 2 && ord(egp[1]) == 3 && ord(egp[2]) <= 4)
  security_note(port: 0, proto: "egp");