Multiple Cisco Products Default SSH Host Keys Security Bypass Vulnerability

# SPDX-FileCopyrightText: 2015 Greenbone AG
# 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("1.3.6.1.4.1.25623.1.0.105319");
  script_cve_id("CVE-2015-4217");
  script_tag(name:"cvss_base", value:"4.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:N/A:N");
  script_version("2023-07-25T05:05:58+0000");

  script_name("Multiple Cisco Products Default SSH Host Keys Security Bypass Vulnerability");

  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/75418");
  script_xref(name:"URL", value:"http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20150625-ironport");

  script_tag(name:"impact", value:"An attacker can exploit this issue to bypass security restrictions and
  perform unauthorized actions. This may aid in further attacks.");

  script_tag(name:"vuldetect", value:"Check the remote ssh host keys.");

  script_tag(name:"insight", value:"The vulnerability is due to the presence of default SSH host keys that are shared across all the installations of WSAv,
  ESAv, and SMAv. An attacker could exploit this vulnerability by obtaining one of the SSH private keys and using it to impersonate or decrypt communication
  between any WSAv, ESAv, or SMAv. An exploit could allow the attacker to decrypt and impersonate secure communication between any virtual content security appliances.");

  script_tag(name:"solution", value:"Updates are available. Please see the vendor advisory for more information.");
  script_tag(name:"summary", value:"Multiple Cisco products are prone to a security-bypass vulnerability.");

  script_tag(name:"affected", value:"Cisco Web Security Virtual Appliance (WSAv), Cisco Email Security Virtual Appliance (ESAv), and Cisco Security Management Virtual Appliance (SMAv) are affected.");
  script_tag(name:"solution_type", value:"VendorFix");

  script_tag(name:"qod_type", value:"remote_active");

  script_tag(name:"last_modification", value:"2023-07-25 05:05:58 +0000 (Tue, 25 Jul 2023)");
  script_tag(name:"creation_date", value:"2015-08-14 13:28:44 +0200 (Fri, 14 Aug 2015)");
  script_category(ACT_GATHER_INFO);
  script_family("CISCO");
  script_copyright("Copyright (C) 2015 Greenbone AG");
  script_dependencies("ssh_detect.nasl", "ssh_proto_version.nasl");
  script_require_ports("Services/ssh", 22);
  script_mandatory_keys("ssh/server_banner/available");

  exit(0);
}

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

port = ssh_get_port(default:22);

fingerprint = get_kb_item("SSH/" + port + "/fingerprint/ssh-rsa");
if( ! fingerprint )
  exit( 0 );

known_fingerprints = make_list( "5e:78:99:f3:11:89:c2:60:ac:63:53:8f:48:d6:8f:a3",
                                "f0:67:d0:64:b5:56:b8:8e:f9:4a:c3:c9:5d:a4:2a:21",
                                "52:f5:c2:f1:b0:7f:dc:bb:eb:70:92:70:be:ed:a5:ee"
                              );

foreach kf ( known_fingerprints )
{
  if( kf == fingerprint )
  {
    report = 'The remote host is using the following default SSH host key: ' + fingerprint + '\n';
    security_message( port:port, data:report );
    exit( 0 );
  }
}

exit( 0 );