Unpassworded 'bash' account

# SPDX-FileCopyrightText: 2004 Michel Arboi
# 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("1.3.6.1.4.1.25623.1.0.15583");
  script_version("2024-04-12T15:39:03+0000");
  script_tag(name:"last_modification", value:"2024-04-12 15:39:03 +0000 (Fri, 12 Apr 2024)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base", value:"7.5");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_cve_id("CVE-1999-0502");
  script_name("Unpassworded 'bash' account");
  script_category(ACT_ATTACK);
  script_family("Malware");
  script_copyright("Copyright (C) 2004 Michel Arboi");
  script_dependencies("find_service.nasl", "telnet.nasl", "ssh_detect.nasl", "gb_default_credentials_options.nasl");
  script_require_ports("Services/telnet", 23, "Services/ssh", 22);
  script_exclude_keys("default_credentials/disable_default_account_checks");

  script_xref(name:"URL", value:"https://packetstormsecurity.com/files/34833/FakeRedhatPatchAnalysis.txt.html");

  script_tag(name:"summary", value:"The account 'bash' has no password set.");

  script_tag(name:"solution", value:"Disable this account and check your system.");

  script_tag(name:"impact", value:"An attacker may use it to gain further privileges on this system.");

  script_tag(name:"insight", value:"This account was probably created by a backdoor installed
  by a fake Linux Redhat patch.

  See the references for more information.");

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

  exit(0);
}

if( get_kb_item( "default_credentials/disable_default_account_checks" ) )
  exit( 0 );

include("ssh_func.inc");
include("telnet_func.inc");
include("default_account.inc");
include("misc_func.inc");
include("port_service_func.inc");

account = "bash";

port = check_account( login:account );
if( port ) {
  security_message( port:port );
  exit( 0 );
}

exit( 99 );