Juniper Junos OS Vulnerability (JSA11246)

##
# (C) Tenable, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(158896);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/24");

  script_cve_id("CVE-2021-31378");
  script_xref(name:"IAVA", value:"2021-A-0478-S");
  script_xref(name:"JSA", value:"JSA11246");

  script_name(english:"Juniper Junos OS Vulnerability (JSA11246)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The version of Junos OS installed on the remote host is affected by a vulnerability as referenced in the JSA11246
advisory.

  - In broadband environments, including but not limited to Enhanced Subscriber Management, (CHAP, PPP, DHCP, etc.), 
    on Juniper Networks Junos OS devices where RADIUS servers are configured for managing subscriber access and a 
    subscriber is logged in and then requests to logout, the subscriber may be forced into a 'Terminating' state 
    by an attacker who is able to send spoofed messages appearing to originate from trusted RADIUS server(s) destined
    to the device in response to the subscriber's request. These spoofed messages cause the Junos OS General 
    Authentication Service (authd) daemon to force the broadband subscriber into this 'Terminating' state which the 
    subscriber will not recover from thereby causing a Denial of Service (DoS) to the endpoint device. Once in the 
    'Terminating'state, the endpoint subscriber will no longer be able to access the network. Restarting the authd 
    daemon on the Junos OS device will temporarily clear the subscribers out of the 'Terminating' state. As long as the 
    attacker continues to send these spoofed packets and subscribers request to be logged out, the subscribers will be 
    returned to the 'Terminating' state thereby creating a persistent Denial of Service to the subscriber. An indicator 
    of compromise may be seen by displaying the output of 'show subscribers summary'. The presence of subscribers in 
    the 'Terminating' state may indicate the issue is occurring. (CVE-2021-31378)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://www.juniper.net/documentation/us/en/software/junos/subscriber-mgmt-sessions/topics/topic-map/general-authentication-service-events-tracing.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?85067fe1");
  # https://supportportal.juniper.net/s/article/2021-10-Security-Bulletin-Junos-OS-An-attacker-sending-spoofed-RADIUS-messages-to-a-Junos-OS-device-configured-for-broadband-services-may-cause-broadband-subscribers-to-remain-stuck-in-a-Terminating-state-CVE-2021-31378
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9dfa0bb2");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper advisory JSA11246");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-31378");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/10/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/10/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/03/14");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:juniper:junos");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Junos Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("junos_version.nasl");
  script_require_keys("Host/Juniper/JUNOS/Version", "Settings/ParanoidReport");

  exit(0);
}

include('junos.inc');


var ver = get_kb_item_or_exit('Host/Juniper/JUNOS/Version');

var vuln_ranges = [
  {'min_ver':'17.3', 'fixed_ver':'17.3R3-S12'},
  {'min_ver':'17.4', 'fixed_ver':'17.4R3-S5'},
  {'min_ver':'18.1', 'fixed_ver':'18.1R3-S13'},
  {'min_ver':'18.2', 'fixed_ver':'18.2R3-S8'},
  {'min_ver':'18.3', 'fixed_ver':'18.3R3-S5'},
  {'min_ver':'18.4', 'fixed_ver':'18.4R2-S8'},
  {'min_ver':'18.4R3', 'fixed_ver':'18.4R3-S9'},
  {'min_ver':'19.1', 'fixed_ver':'19.1R3-S6'},
  {'min_ver':'19.2', 'fixed_ver':'19.2R1-S7'},
  {'min_ver':'19.2R2', 'fixed_ver':'19.2R3-S3'},
  {'min_ver':'19.3', 'fixed_ver':'19.3R2-S6'},
  {'min_ver':'19.3R3', 'fixed_ver':'19.3R3-S3'},
  {'min_ver':'19.4', 'fixed_ver':'19.4R1-S4'},
  {'min_ver':'19.4R2', 'fixed_ver':'19.4R3-S3'},
  {'min_ver':'20.1', 'fixed_ver':'20.1R3'},
  {'min_ver':'20.2', 'fixed_ver':'20.2R3-S1'},
  {'min_ver':'20.3', 'fixed_ver':'20.3R3'},
  {'min_ver':'20.4', 'fixed_ver':'20.4R3'},
  {'min_ver':'21.1', 'fixed_ver':'21.1R2'}
];

var fix = junos_compare_range(target_version:ver, vuln_ranges:vuln_ranges);
if (empty_or_null(fix)) audit(AUDIT_INST_VER_NOT_VULN, 'Junos OS', ver);
var report = get_report(ver:ver, fix:fix);
security_report_v4(severity:SECURITY_WARNING, port:0, extra:report);