Vulnerabilities > CVE-2020-5876 - Cleartext Transmission of Sensitive Information vulnerability in F5 products

047910
CVSS 8.1 - HIGH
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
high complexity
f5
CWE-319
nessus

Summary

On BIG-IP 15.0.0-15.0.1.3, 14.1.0-14.1.2.3, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, a race condition exists where mcpd and other processes may make unencrypted connection attempts to a new configuration sync peer. The race condition can occur when changing the ConfigSync IP address of a peer, adding a new peer, or when the Traffic Management Microkernel (TMM) first starts up.

Vulnerable Configurations

Part Description Count
Application
F5
1128

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Session Sidejacking
    Session sidejacking takes advantage of an unencrypted communication channel between a victim and target system. The attacker sniffs traffic on a network looking for session tokens in unencrypted traffic. Once a session token is captured, the attacker performs malicious actions by using the stolen token with the targeted application to impersonate the victim. This attack is a specific method of session hijacking, which is exploiting a valid session token to gain unauthorized access to a target system or information. Other methods to perform a session hijacking are session fixation, cross-site scripting, or compromising a user or server machine and stealing the session token.
  • Footprinting
    An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
  • Harvesting Usernames or UserIDs via Application API Event Monitoring
    An attacker hosts an event within an application framework and then monitors the data exchanged during the course of the event for the purpose of harvesting any important data leaked during the transactions. One example could be harvesting lists of usernames or userIDs for the purpose of sending spam messages to those users. One example of this type of attack involves the attacker creating an event within the sub-application. Assume the attacker hosts a "virtual sale" of rare items. As other users enter the event, the attacker records via MITM proxy the user_ids and usernames of everyone who attends. The attacker would then be able to spam those users within the application using an automated script.
  • Signature Spoofing by Mixing Signed and Unsigned Content
    An attacker exploits the underlying complexity of a data structure that allows for both signed and unsigned content, to cause unsigned data to be processed as though it were signed data.
  • Passively Sniff and Capture Application Code Bound for Authorized Client
    Attackers can capture application code bound for the client and can use it, as-is or through reverse-engineering, to glean sensitive information or exploit the trust relationship between the client and server. Such code may belong to a dynamic update to the client, a patch being applied to a client component or any such interaction where the client is authorized to communicate with the server.

Nessus

NASL familyF5 Networks Local Security Checks
NASL idF5_BIGIP_SOL32121038.NASL
descriptionA race condition exists where mcpd and other processes may make unencrypted connection attempts to a new configuration sync peer. The race condition can occur when changing the ConfigSync IP address of a peer, adding a new peer, or when the Traffic Management Microkernel (TMM) first starts up. (CVE-2020-5876) Impact The race condition gives a small window of opportunity for an attacker to takeover the connection and spoof a trusted peer device to extract and/or modify sensitive information on the system. This vulnerability is only present when the BIG-IP system is configured as part of a ConfigSync high availability (HA) device group.
last seen2020-05-09
modified2020-04-30
plugin id136135
published2020-04-30
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/136135
titleF5 Networks BIG-IP : BIG-IP mcpd vulnerability (K32121038)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from F5 Networks BIG-IP Solution K32121038.
#
# The text description of this plugin is (C) F5 Networks.
#

include("compat.inc");

if (description)
{
  script_id(136135);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/22");

  script_cve_id("CVE-2020-5876");

  script_name(english:"F5 Networks BIG-IP : BIG-IP mcpd vulnerability (K32121038)");
  script_summary(english:"Checks the BIG-IP version.");

  script_set_attribute(
    attribute:"synopsis",
    value:"The remote device is missing a vendor-supplied security patch."
  );
  script_set_attribute(
    attribute:"description",
    value:
"A race condition exists where mcpd and other processes may make
unencrypted connection attempts to a new configuration sync peer. The
race condition can occur when changing the ConfigSync IP address of a
peer, adding a new peer, or when the Traffic Management Microkernel
(TMM) first starts up. (CVE-2020-5876)

Impact

The race condition gives a small window of opportunity for an attacker
to takeover the connection and spoof a trusted peer device to extract
and/or modify sensitive information on the system. This vulnerability
is only present when the BIG-IP system is configured as part of a
ConfigSync high availability (HA) device group."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://support.f5.com/csp/article/K32121038"
  );
  script_set_attribute(
    attribute:"solution",
    value:
"Upgrade to one of the non-vulnerable versions listed in the F5
Solution K32121038."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/PR:N/UI:N/S:U/C:H/I:H/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-2020-5876");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  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:/a:f5:big-ip_advanced_firewall_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_acceleration_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_security_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_application_visibility_and_reporting");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_global_traffic_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_link_controller");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_local_traffic_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:f5:big-ip_policy_enforcement_manager");
  script_set_attribute(attribute:"cpe", value:"cpe:/h:f5:big-ip");

  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:"2020/04/30");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"F5 Networks Local Security Checks");

  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");

  exit(0);
}


include("f5_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
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");

sol = "K32121038";
vmatrix = make_array();

# AFM
vmatrix["AFM"] = make_array();
vmatrix["AFM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["AFM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# AM
vmatrix["AM"] = make_array();
vmatrix["AM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["AM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# APM
vmatrix["APM"] = make_array();
vmatrix["APM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["APM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# ASM
vmatrix["ASM"] = make_array();
vmatrix["ASM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["ASM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# AVR
vmatrix["AVR"] = make_array();
vmatrix["AVR"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["AVR"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# GTM
vmatrix["GTM"] = make_array();
vmatrix["GTM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["GTM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# LC
vmatrix["LC"] = make_array();
vmatrix["LC"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["LC"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# LTM
vmatrix["LTM"] = make_array();
vmatrix["LTM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["LTM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");

# PEM
vmatrix["PEM"] = make_array();
vmatrix["PEM"]["affected"  ] = make_list("15.0.0-15.0.1","14.0.0-14.1.2","13.1.0-13.1.3","12.1.0-12.1.5","11.6.1-11.6.5");
vmatrix["PEM"]["unaffected"] = make_list("15.1.0","14.1.2.5","13.1.3.4","12.1.5.1","11.6.5.2");


if (bigip_is_affected(vmatrix:vmatrix, sol:sol))
{
  if (report_verbosity > 0) security_warning(port:0, extra:bigip_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = bigip_get_tested_modules();
  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 any of the affected modules");
}