CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
35.9%
When a user connects to a VPN using BIG-IP Edge Client over an unsecure network, BIG-IP Edge Client responds to authentication requests over HTTP while sending probes for captive portal detection.
(CVE-2020-5893)
Impact
An attacker can use a man-in-the-middle (MITM) attack by deploying a maliciouscaptive portal to exploit this vulnerability to obtain the encryptedNT Lan Manager (NTLM) challenge response. This can be used to carry out brute force dictionary attacks or NTLM relay attacks if the attacker has access to the Active Directory network.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from F5 Networks BIG-IP Solution K97733133.
#
# The text description of this plugin is (C) F5 Networks.
#
include('compat.inc');
if (description)
{
script_id(138068);
script_version("1.6");
script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/03");
script_cve_id("CVE-2020-5893");
script_name(english:"F5 Networks BIG-IP : BIG-IP APM Edge Client vulnerability (K97733133)");
script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
script_set_attribute(attribute:"description", value:
"When a user connects to a VPN using BIG-IP Edge Client over an
unsecure network, BIG-IP Edge Client responds to authentication
requests over HTTP while sending probes for captive portal detection.
(CVE-2020-5893)
Impact
An attacker can use a man-in-the-middle (MITM) attack by deploying a
maliciouscaptive portal to exploit this vulnerability to obtain the
encryptedNT Lan Manager (NTLM) challenge response. This can be used to
carry out brute force dictionary attacks or NTLM relay attacks if the
attacker has access to the Active Directory network.");
script_set_attribute(attribute:"see_also", value:"https://my.f5.com/manage/s/article/K97733133");
script_set_attribute(attribute:"solution", value:
"Upgrade to one of the non-vulnerable versions listed in the F5 Solution K97733133.");
script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-5893");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/30");
script_set_attribute(attribute:"patch_publication_date", value:"2020/04/29");
script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/02");
script_set_attribute(attribute:"potential_vulnerability", value:"true");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_access_policy_manager");
script_set_attribute(attribute:"cpe", value:"cpe:/h:f5:big-ip");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"F5 Networks Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2020-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("f5_bigip_detect.nbin");
script_require_keys("Host/local_checks_enabled", "Host/BIG-IP/hotfix", "Host/BIG-IP/modules", "Host/BIG-IP/version", "Settings/ParanoidReport");
exit(0);
}
include('f5_func.inc');
if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var version = get_kb_item('Host/BIG-IP/version');
if ( ! version ) audit(AUDIT_OS_NOT, 'F5 Networks BIG-IP');
if ( isnull(get_kb_item('Host/BIG-IP/hotfix')) ) audit(AUDIT_KB_MISSING, 'Host/BIG-IP/hotfix');
if ( ! get_kb_item('Host/BIG-IP/modules') ) audit(AUDIT_KB_MISSING, 'Host/BIG-IP/modules');
if (report_paranoia < 2) audit(AUDIT_PARANOID);
var sol = 'K97733133';
var vmatrix = {
'APM': {
'affected': [
'15.0.0-15.1.0','14.0.0-14.1.2','13.1.0-13.1.3','12.1.0-12.1.5','11.6.1-11.6.5'
],
'unaffected': [
'15.1.0.2','14.1.2.4','13.1.4','12.1.5.2','11.6.5.2'
],
}
};
if (bigip_is_affected(vmatrix:vmatrix, sol:sol))
{
var extra = NULL;
if (report_verbosity > 0) extra = bigip_report_get();
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : extra
);
}
else
{
var tested = bigip_get_tested_modules();
var audit_extra = 'For BIG-IP module(s) ' + tested + ',';
if (tested) audit(AUDIT_INST_VER_NOT_VULN, audit_extra, version);
else audit(AUDIT_HOST_NOT, 'running the affected module APM');
}
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:M/Au:N/C:P/I:N/A:N
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
35.9%