Vulnerabilities > CVE-2018-0008 - Improper Authentication vulnerability in Juniper Junos

047910
CVSS 6.2 - MEDIUM
Attack vector
PHYSICAL
Attack complexity
LOW
Privileges required
HIGH
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
low complexity
juniper
CWE-287
nessus

Summary

An unauthenticated root login may allow upon reboot when a commit script is used. A commit script allows a device administrator to execute certain instructions during commit, which is configured under the [system scripts commit] stanza. Certain commit scripts that work without a problem during normal commit may cause unexpected behavior upon reboot which can leave the system in a state where root CLI login is allowed without a password due to the system reverting to a "safe mode" authentication state. Lastly, only logging in physically to the console port as root, with no password, will work. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D71 on SRX; 12.3X48 versions prior to 12.3X48-D55 on SRX; 14.1 versions prior to 14.1R9; 14.1X53 versions prior to 14.1X53-D40 on QFX, EX; 14.2 versions prior to 14.2R7-S9, 14.2R8; 15.1 versions prior to 15.1F5-S7, 15.1F6-S8, 15.1R5-S6, 15.1R6; 15.1X49 versions prior to 15.1X49-D110 on SRX; 15.1X53 versions prior to 15.1X53-D232 on QFX5200/5110; 15.1X53 versions prior to 15.1X53-D49, 15.1X53-D470 on NFX; 15.1X53 versions prior to 15.1X53-D65 on QFX10K; 16.1 versions prior to 16.1R2. No other Juniper Networks products or platforms are affected by this issue.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Nessus

NASL familyJunos Local Security Checks
NASL idJUNIPER_JSA10835.NASL
descriptionAccording to its self-reported version number, the remote Junos device is affected by a authentication bypass vulnerability.
last seen2020-06-01
modified2020-06-02
plugin id106392
published2018-01-26
reporterThis script is Copyright (C) 2018 Tenable Network Security, Inc.
sourcehttps://www.tenable.com/plugins/nessus/106392
titleJuniper Junos Commit Script Handling Local Console Port Access Weakness Vulnerability (JSA10835)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(106392);
  script_version("1.4");
  script_cvs_date("Date: 2018/07/12 19:01:16");

  script_cve_id("CVE-2018-0008");
  script_xref(name:"JSA", value:"JSA10835");

  script_name(english:"Juniper Junos Commit Script Handling Local Console Port Access Weakness Vulnerability (JSA10835)");
  script_summary(english:"Checks the Junos version and build date.");

  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 number, the remote Junos device
is affected by a authentication bypass vulnerability.");
  # https://kb.juniper.net/InfoCenter/index?page=content&id=JSA10835&actp=METADATA
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7c3fa562");
  script_set_attribute(attribute:"solution", value:
"Apply the relevant Junos software release referenced in
Juniper advisory JSA10835.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/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:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/01/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/26");

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

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

  script_copyright(english:"This script is Copyright (C) 2018 Tenable Network Security, Inc.");

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

  exit(0);
}

include("audit.inc");
include("junos_kb_cmd_func.inc");

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

# Affected:
# 12.1X46 versions prior to 12.1X46-D71 on SRX
# 12.3X48 versions prior to 12.3X48-D55 on SRX
# 14.1 versions prior to 14.1R9
# 14.1X53 versions prior to 14.1X53-D40 on QFX, EX
# 14.2 versions prior to 14.2R7-S9, 14.2R8
# 15.1 versions prior to 15.1F5-S7, 15.1F6-S8, 15.1R5-S6, 15.1R6
# 15.1X49 versions prior to 15.1X49-D110 on SRX
# 15.1X53 versions prior to 15.1X53-D232 on QFX5200/5110
# 15.1X53 versions prior to 15.1X53-D49, 15.1X53-D470 on NFX
# 15.1X53 versions prior to 15.1X53-D65 on QFX10K
# 16.1 versions prior to 16.1R2
fixes = make_array();

if (model =~ "^SRX")
{
  fixes['12.1X46'] = '12.1X46-D71';
  fixes['12.3X48'] = '12.3X48-D55';
  fixes['15.1X49'] = '15.1X49-D110';
}
else if (model =~ "^EX")
{
  fixes['14.1X53'] = '14.1X53-D40';
}
else if (model =~ "^NFX")
{
  fixes['15.1X53'] = '15.1X53-D49'; # or 15.1X53-D470
}
else if (model =~ "^QFX5(200|110)")
{
  fixes['14.1X53'] = '14.1X53-D40';
  fixes['15.1X53'] = '15.1X53-D232';
}
else if (model =~ "^QFX10K")
{
  fixes['14.1X53'] = '14.1X53-D40';
  fixes['15.1X53'] = '15.1X53-D65';
}
else if (model =~ "^QFX")
{
  fixes['14.1X53'] = '14.1X53-D40';

}

fixes['14.1'] = '14.1R9';
fixes['14.2'] = '14.2R8';
if (ver =~ "^15\.1F5")
  fixes['15.1'] = '15.1F5-S7';
else if (ver =~ "^15\.1F6")
  fixes['15.1'] = '15.1F6-S8';
else if (ver =~ "^15\.1R5")
  fixes['15.1'] = '15.1R5-S6';
else
  fixes['15.1'] = '15.1R6';
fixes['16.1'] = '16.1R2';

fix = check_junos(ver:ver, fixes:fixes, exit_on_fail:TRUE);

override = FALSE;

junos_report(ver:ver, fix:fix, override:override, severity:SECURITY_WARNING);