The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
Unchanged
S
An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
Below is a copy: FortiOS 6.0.6 / FortiClientWindows 6.0.6 / FortiClientMac 6.2.1 XOR Encryption
SEC Consult Vulnerability Lab Security Advisory < 20191125-0 >
=======================================================================
title: FortiGuard XOR Encryption
product: Multiple Fortinet Products (see Vulnerable / tested versions)
vulnerable version: Multiple (see Vulnerable / tested versions)
fixed version: Multiple (see Solution)
CVE number: CVE-2018-9195
impact: High
homepage: https://www.fortinet.com
found: 2018-05-16
by: Stefan Viehbck (Office Vienna)
SEC Consult Vulnerability Lab
An integrated part of SEC Consult
Europe | Asia | North America
https://www.sec-consult.com
=======================================================================
Vendor description:
-------------------
"From the start, the Fortinet vision has been to deliver broad, truly
integrated, high-performance security across the IT infrastructure.
We provide top-rated network and content security, as well as secure access
products that share intelligence and work together to form a cooperative
fabric. Our unique security fabric combines Security Processors, an intuitive
operating system, and applied threat intelligence to give you proven security,
exceptional performance, and better visibility and control--while providing
easier administration."
Source: https://www.fortinet.com/corporate/about-us/about-us.html
Business recommendation:
------------------------
The vendor provides a patch and users of affected products are urged to
immediately upgrade to the latest version available.
Vulnerability overview/description:
-----------------------------------
Fortinet products, including FortiGate and Forticlient regularly send
information to Fortinet servers (DNS: guard.fortinet.com) on
- UDP ports 53, 8888 and
- TCP port 80 (HTTP POST /fgdsvc)
This cloud communication is used for the FortiGuard Web Filter feature (https://fortiguard.com/webfilter),
FortiGuard AntiSpam feature (https://fortiguard.com/updates/antispam)
and FortiGuard AntiVirus feature (https://fortiguard.com/updates/antivirus).
The messages are encrypted using XOR "encryption" with a static key.
The protocol messages contain the following types of information:
**Serial number of the Fortinet product installation** (product type + unique ID).
This information allows an attacker who can **passively monitor** internet traffic to:
- learn which Fortinet products and product types an organization uses
(this is valuable for information gathering, see EquationGroup Fortigate exploits)
- learn which FortiClient installations are part of an organization
- use the FortiClient serial number as a unique identifier to track an individual as
he/she travels the world
**Full HTTP URLs of users web surfing activity** (Web Filter feature).
This information allows an attacker who can **passively monitor** internet traffic
to spy on users' web surfing activity. In cases where SSL inspection is enabled,
even the URLs of HTTPS-encrypted communication are sent via this protocol,
effectively breaking the confidentiality of SSL/TLS.
**Unspecified email data** (AntiSpam feature).
We do not have any further information on what kind of information is sent by the
AntiSpam feature.
**Unspecified AntiVirus data** (AntiVirus feature).
We do not have any further information on what kind of information is sent by the
AntiVirus feature.
By **intercepting and manipulating** internet traffic an attacker can:
Manipulate the responses for FortiGuard Web Filter, AntiSpam and AntiVirus features.
Proof of concept:
-----------------
The following Python 3 script decrypts a FortiGuard message (the static XOR key
has been removed from this advisory).
```python
from itertools import cycle
def forti_xor(s1):
xor_key = **removed**
message = ''.join(chr(c ^ k) for c, k in zip(s1, cycle(xor_key)))
return message
r1=bytes.fromhex('6968766f606e776c2d2d21262138475c5b5a475b545e475c6b6a776b646e776c6b6a772b646e776c6b6a776b646e776c6b6a776bbadf04036b6a776c616a846f')
print(repr(forti_xor(r1)))
```
In this case the encrypted message contents are:
'\x02\x02\x01\x04\x04\x00\x00\x00FGVMEV0000000000\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00@\x00\x00\x00\x00\x00\x00...'
Another example:
'\x02\x01\x02\x04I\x03\x00FG100D3G00000000\x00\x00\...x00\x00+https://v10.vortex-win.data.microsoft.com/\x00'
Vulnerable / tested versions:
-----------------------------
The following FortiOS versions are affected according to the vendor:
* FortiOS 6.0.6 and below
* FortiClientWindows 6.0.6 and below
* FortiClientMac 6.2.1 and below
The security advisory of the vendor can be found at:
https://fortiguard.com/psirt/FG-IR-18-100
Vendor contact timeline:
------------------------
2018-05-17: Contacting vendor through [email protected], sending advisory with
public PGP key
2018-05-17: Auto-Response: "Thank you for contacting us regarding your
inquiry. We have created a PSIRT ticket for this inquiry"
2018-05-17: Response: "Thank you to report us this vulnerability. I created
an internal incident and I will communicate further with you while
I'm investigating the impact of this."
2018-05-28: Requesting update, "If we don't get an appropriate response (see my
initial email) by the end of next week, we will consider disclosing
the vulnerability without further coordination."
2018-05-28: Auto-Response: "Thank you for contacting us regarding your inquiry.
We have created a PSIRT ticket for this inquiry"
2018-06-05: Requesting update again, "This is the final attempt to contact you",
plus reaching out to Fortinet via Twitter, LinkedIn.
2018-06-05: First response after 3 weeks, developers are working on a fix,
"Please therefore kindly wait for further updates, while we are
coordinating various stakeholders (including FortiGuard servers
maintainers) for a fix."
2018-06-06: Requesting conference call.
2018-06 - 2019-11: Multiple conference calls, discussing technical details, agreeing
on disclosure time
2019-03-28: Fix released in FortiOS 6.2.0
2019-04-01: Fix issued on FortiGuard server side
2019-11-13: Fix released for FortiOS branch 6.0, version 6.0.7
2019-11-25: Public release of security advisory
Solution:
---------
The vendor provides updated versions for the affected products:
* FortiOS 6.0.7 or 6.2.0
* FortiClientWindows 6.2.0
* FortiClientMac 6.2.2
The security advisory of the vendor can be found at: https://fortiguard.com/psirt/FG-IR-18-100
Workaround:
-----------
None
Advisory URL:
-------------
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SEC Consult Vulnerability Lab
SEC Consult
Europe | Asia | North America
About SEC Consult Vulnerability Lab
The SEC Consult Vulnerability Lab is an integrated part of SEC Consult. It
ensures the continued knowledge gain of SEC Consult in the field of network
and application security to stay ahead of the attacker. The SEC Consult
Vulnerability Lab supports high-quality penetration testing and the evaluation
of new offensive and defensive technologies for our customers. Hence our
customers obtain the most current information about vulnerabilities and valid
recommendation about the risk profile of new technologies.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Send us your application https://www.sec-consult.com/en/career/index.html
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Contact our local offices https://www.sec-consult.com/en/contact/index.html
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mail: research at sec-consult dot com
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EOF Stefan Viehbck / @2019
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