CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
Percentile
42.6%
According to its self-reported version, the remote Juniper Junos OS device is affected by a denial of service (DoS) vulnerability. When a device running Juniper Networks Junos OS with MPC7, MPC8, or MPC9 line cards installed and the system is configured for inline IP reassembly, used by L2TP, MAP-E, GRE, and IPIP, the packet forwarding engine (PFE) will become disabled upon receipt of large packets requiring fragmentation. By continuously sending fragmented packets that cannot be reassembled, an unauthenticated, remote attacker can repeatedly disable the PFE causing a DoS.
Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.
#
# (C) Tenable Network Security, Inc.
#
include('compat.inc');
if (description)
{
script_id(138907);
script_version("1.5");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");
script_cve_id("CVE-2020-1655");
script_xref(name:"JSA", value:"JSA11041");
script_xref(name:"IAVA", value:"2020-A-0320-S");
script_name(english:"Juniper Junos MX Series PFE Large Packet DoS (JSA11041)");
script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
script_set_attribute(attribute:"description", value:
"According to its self-reported version, the remote Juniper Junos OS device is affected by a denial of service (DoS)
vulnerability. When a device running Juniper Networks Junos OS with MPC7, MPC8, or MPC9 line cards installed and the
system is configured for inline IP reassembly, used by L2TP, MAP-E, GRE, and IPIP, the packet forwarding engine (PFE)
will become disabled upon receipt of large packets requiring fragmentation. By continuously sending fragmented packets
that cannot be reassembled, an unauthenticated, remote attacker can repeatedly disable the PFE causing a DoS.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
script_set_attribute(attribute:"see_also", value:"https://kb.juniper.net/JSA11041");
script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in Juniper advisory JSA11041");
script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:L");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-1655");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/07/08");
script_set_attribute(attribute:"patch_publication_date", value:"2020/07/08");
script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/24");
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) 2020-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("junos_version.nasl");
script_require_keys("Host/Juniper/JUNOS/Version", "Host/Juniper/model");
exit(0);
}
include('junos.inc');
model = get_kb_item_or_exit('Host/Juniper/model');
if (model !~ '^MX')
audit(AUDIT_HOST_NOT, 'an affected model');
if (report_paranoia < 2)
audit(AUDIT_PARANOID);
ver = get_kb_item_or_exit('Host/Juniper/JUNOS/Version');
fixes = make_array();
fixes['17.2'] = '17.2R3-S4';
fixes['17.3'] = '17.3R3-S8';
if (ver =~ "^17\.4R3")
fixes['17.4'] = '17.4R3-S2';
else
fixes['17.4'] = '17.4R2-S10';
fixes['18.1'] = '18.1R3-S10';
fixes['18.2'] = '18.2R3-S3';
fixes['18.2X75'] = '18.2X75-D41';
if (ver =~ "^18\.3R3")
fixes['18.3'] = '18.3R3-S1';
else if (ver =~ "^18\.3R2")
fixes['18.3'] = '18.3R2-S4';
else
fixes['18.3'] = '18.3R1-S7';
if (ver =~ "^18\.4R1")
fixes['18.4'] = '18.4R1-S7';
else
fixes['18.4'] = '18.4R2-S4';
if (ver =~ "^19\.1R1")
fixes['19.1'] = '19.1R1-S5';
else
fixes['19.1'] = '19.1R2-S1';
fixes['19.2'] = '19.2R1-S4';
fixes['19.3'] = '19.3R2-S2';
fix = check_junos(ver:ver, fixes:fixes, exit_on_fail:TRUE);
report = get_report(ver:ver, fix:fix);
security_report_v4(severity:SECURITY_WARNING, port:0, extra:report);
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
Percentile
42.6%