OpenSSH < 3.2.3 YP Netgroups Authentication Bypass

#
# (C) Tenable, Inc.
#

include("compat.inc");

if (description)
{
  script_id(44072);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/27");

  script_cve_id("CVE-2002-0765");
  script_bugtraq_id(4803);

  script_name(english:"OpenSSH < 3.2.3 YP Netgroups Authentication Bypass");
  script_summary(english:"Checks SSH banner");

  script_set_attribute(
    attribute:"synopsis",
    value:"The remote SSH server has an authentication bypass vulnerability."
  );
  script_set_attribute(
    attribute:"description",
    value:
"According to its banner, the version of OpenSSH running on the remote
host is older than 3.2.3.  It therefore may be affected by an
authentication bypass issue.  On systems using YP with netgroups, sshd
authenticates users via ACL by checking for the requested username and
password.  Under certain conditions when doing ACL checks, it may
instead use the password entry of a different user for authentication. 
This means unauthorized users could authenticate successfully, and
authorized users could be locked out."
  );
  script_set_attribute(attribute:"see_also",value:"http://monkey.org/openbsd/archive/bugs/0205/msg00141.html");
  script_set_attribute(attribute:"see_also",value:"https://www.openssh.com/txt/release-3.2.3");
  script_set_attribute(attribute:"see_also",value:"http://www.openbsd.org/errata31.html#sshbsdauth");
  script_set_attribute(
    attribute:"solution",
    value:"Upgrade to OpenSSH 3.2.3 or later."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2002/05/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2002/05/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2011/10/04");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:openbsd:openssh");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Gain a shell remotely");

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("openssh_detect.nbin");
  script_require_keys("installed_sw/OpenSSH");
  script_require_ports("Services/ssh", 22);

  exit(0);
}

include('backport.inc');
include('vcf.inc');
include('vcf_extras.inc');

var port = get_service(svc:'ssh', default:22, exit_on_fail:TRUE);
var app_info = vcf::openssh::get_app_info(app:'OpenSSH', port:port);

vcf::check_all_backporting(app_info:app_info);

var constraints = [
  {'fixed_version' : '3.2.3'}
];

vcf::openssh::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);