The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity
High
AC
The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques. The attacker must have additional methods available to bypass security measures in place. For example, circumvention of address space randomization (ASLR) or data execution prevention must be performed for the attack to be successful. Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
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.
Scope
S
An exploited vulnerability can affect resources beyond the security scope managed by the security authority that is managing the vulnerable component. This is often referred to as a 'privilege escalation,' where the attacker can use the exploited vulnerability to gain control of resources that were not intended or authorized.
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: Microsoft Windows SCF File 'Open File Security Warning' Feature Bypass Vulnerability
# Exploit Title: Microsoft Windows 'SCF' File 'Open File Security Warning' Feature Bypass Vulnerability
# Google Dork: N/A
# Date: August 3, 2018
# Exploit Author: Eduardo Braun Prado
# Vendor Homepage: http://www.microsoft.com/
# Software Link: http://www.microsoft.com/
# Version: Windows 7 SP1, 8.1 with full patches up to July, 2018. both x86 and x64 architectures, all available OS specific versions like eg. Enterprise, Ultimate, Starter etc..
# Tested on: Windows 7 SP1, 8.1 with full patches up to July, 2018.
# CVE : n/a
Vendor contacted on: July 28, 2018. Full details of vulnerability were given with a PoC.
Vendor replied on July 31, 2018 asking for specific OS versions and a PoC.
Again I sent the already sent PoC and told them the already witten versions, which as enlightened on the vulnerability title, doesn't affect latest Windows 10 release.
On August, 2, 2018 they replied: "We have concluded our investigation and determined the issue does not meet the bar for a security update."
Then I replied back asking as to why not release a patch since this could be abused with other exploits to potentially compromise affected OS versions. They replied, at the same day:
"The severity rating for this would normally warrant vnext consideration but testing this with MOTW tagging in RS4 shows correct behavior of a security warning."
So, to summarize, they are not patching it basicly because it doesn't affect latest build of Windows 10. This is strategic: "To get people to upgrade to Windows 10 ASAP" even though they are commited to release security related updates for all Windows versions in their extended life support, which is the case for 7 and 8.1.
PoC: To reproduce the issue, get a valid ".SCF" file and host on a web server. Then using an affected Windows version, download the file to disk using any web browser or E-mail Client software that appends the "Mark Of The Web" (MOTW) to downloaded files.
Upon trying to open the file, a security warning should be displayed because '.SCF' is considered a "high risk file type", for several ages, however the library responsible for checking the file type and the 'Security Zone' it comes from, fails to display it, and the file is executed automatically.
Below is the link for some valid SCF files. Microsoft gives no documentation whatsoever on this particular file type, but given the few examples, it's likely that it can cause damage to the system:
https : // social . technet . microsoft . com/Forums/office/en-US/74b0e6f5-f90f-42b5-9658-3fe26f9db2d9/scf-files-windows-explorer-command-file-quotscriptingquot-documentation ? forum=ITCG
PS: Remove the spaces...this was done on purpose so some AVs and other security related software doesnt flag this article as "malicious".
For those who are curious about what this file type can do...so far we can do some neat stuff:
- Extension hiding (even when Windows is setup to show extensions) -> good on spoofing attacks
- Remote Icon retrieval -> good to force the OS and libraries responsible for displaying folders on Windows OSes to automatically attempt connection to SMB shares.
- Arbitrary icon set -> this can be used along the extension hiding issue to trick users into thinking this file is actually of another type like picture or text.
Researchers world wide: Feel free to dig this deeper; You may find even more obscure stuff "hiding" with this file type.
- Eduardo.