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#
# This script was written by Renaud Deraison <deraison@cvs.nessus.org>
#
# See the Nessus Scripts License for details
#
if(description)
{
script_id(10550);
name["english"] = "Obtain processes list via SNMP";
name["francais"] = "Enumeration des processus par SNMP";
script_name(english:name["english"],
francais:name["francais"]);
desc["english"] = "
This script uses SNMP to obtain the list of
the processes that are running on the remote host.";
desc["francais"] = "
Ce script utilise SNMP pour obtenir la liste des
processus qui tournent sur la machine distante";
script_description(english:desc["english"],
francais:desc["francais"]);
summary["english"] = "Enumerates processes via SNMP";
summary["francais"] = "Enumeration des processus par SNMP";
script_summary(english:summary["english"],
francais:summary["francais"]);
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2000 Renaud Deraison");
family["english"] = "SNMP";
script_family(english:family["english"]);
script_dependencies("snmp_default_communities.nasl");
script_require_keys("SNMP/community");
exit(0);
}
#--------------------------------------------------------------------#
# Forges an SNMP GET NEXT packet #
#--------------------------------------------------------------------#
function get_next(community, id, object)
{
len = strlen(community);
#display("len : ", len, "\n");
len = len % 256;
tot_len = 4 + strlen(community) + 12 + strlen(object) + 4;
# display(hex(tot_len), "\n");
_r = raw_string(0x30, tot_len, 0x02, 0x01, 0x00, 0x04, len);
o_len = strlen(object) + 2;
a_len = 13 + strlen(object);
_r = _r + community + raw_string( 0xA1,
a_len, 0x02, 0x01, id, 0x02, 0x01, 0x00, 0x02,
0x01, 0x00, 0x30,o_len) + object + raw_string(0x05, 0x00);
# display("len : ", strlen(_r), "\n");
return(_r);
}
#---------------------------------------------------------------------#
# Extracts the object from a reply #
#---------------------------------------------------------------------#
function extract_obj(data)
{
if(ord(data[2]) == 2)
{
cmty_len = ord(data[6]);
off = 18 + cmty_len;
}
else
{
cmty_len = ord(data[7]);
off = 20 + cmty_len;
}
len_payload = ord(data[off]);
_obj = "";
total_len = ord(data[off+5])+6;
for(i=4;i<total_len;i=i+1)
{
_obj = _obj + raw_string(ord(data[off+i]));
}
_len = strlen(_obj) + 2;
# display(">len : ", _len, "\n");
_len = _len % 255;
_obj2 = raw_string(0x30, _len);
_obj = _obj2 + _obj;
l = strlen(_obj);
# for(i=0;i<l;i=i+1)display(hex(ord(_obj[i])), " ");
# display("\n");
return(_obj);
}
#---------------------------------------------------------------------#
# Extracts the data from a reply #
#---------------------------------------------------------------------#
function extract_data(data)
{
if(ord(data[2]) == 2)
{
cmty_len = ord(data[6]);
off1 = 18 + cmty_len;
off = 39 + cmty_len;
}
else
{
cmty_len = ord(data[7]);
off1 = 20 + cmty_len;
off = 41 + cmty_len;
}
off = 18 + ord(data[off1+5])+ 7 + cmty_len;
# display("OFF = ", off, "\n");
_len = ord(data[off]);
_data = "";
#display("OFF :" , off, " _LEN : ", hex(_len), "\n");
#_len = ord(data[off+18+_len]);
for(i=0;i<_len;i=i+1){
_data = _data + raw_string(ord(data[off+i+1]));
}
#display("data : ", _data, "\n");
return(_data);
}
community = get_kb_item("SNMP/community");
if(!community)community = "public";
prcss = "";
soc = open_sock_udp(161);
first = raw_string(0x30, 0x11, 0x06, 0x0D,
0x2B, 0x06, 0x01, 0x04, 0x01, 0x0b, 0x02, 0x03,
0x01, 0x04, 0x02, 0x01, 0x16);
id = 2;
req = get_next(id:id, community:community, object:first);
send(socket:soc, data:req);
r = recv(socket:soc, length:1025);
if(strlen(r) < 48)exit(0);
nxt = extract_obj(data:r);
data = extract_data(data:r);
#display(data, "\n");
if(strlen(data))
{
prcss = string(prcss, ". ", data, "\n");
}
for(z=1;z<255;z=z+1)
{
req = get_next(id:id+z, community:community, object:nxt);
send(socket:soc, data:req);
r = recv(socket:soc, length:1025);
#display("PKT LEN : ", strlen(r), "\n");
if(strlen(r) < 48)
{
z = 256;
}
else
{
nxt = extract_obj(data:r);
data = extract_data(data:r);
if(strlen(data))
{
#display(data, "\n");
prcss = string(prcss, ". ", data, "\n");
}
}
}
if(strlen(prcss))
{
report = string(
"It was possible to obtain the list of processes of the\n",
"remote host via SNMP : \n\n", prcss, "\n",
"An attacker may use this information to gain more knowledge about\n",
"the target host.\n",
"Solution : disable the SNMP service on the remote host if you do not\n",
" use it, or filter incoming UDP packets going to this port\n",
"Risk factor : Low");
security_warning(protocol:"udp", port:161, data:report);
}
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