CVE-2018-0826 : Detail

CVE-2018-0826

7
/
High
48.11%V3
Local
2018-02-15
02h00 +00:00
2024-09-16
16h37 +00:00
CVE.org
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CVE Descriptions

Windows Storage Services in Windows 10 versions 1511, 1607, 1703 and 1709, Windows Server 2016 and Windows Server, version 1709 allows an elevation of privilege vulnerability due to the way objects are handled in memory, aka "Windows Storage Services Elevation of Privilege Vulnerability".

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE Other No informations.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 7 HIGH CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Local

A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file.

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

High

A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker is authorized with (i.e. requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics

 [email protected]
V2 4.4 AV:L/AC:M/Au:N/C:P/I:P/A:P [email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 44152

Publication date : 2018-02-19 23h00 +00:00
Author : Google Security Research
EDB Verified : Yes

Windows: StorSvc SvcMoveFileInheritSecurity Arbitrary File Creation EoP Platform: Windows 10 1709 (not tested earlier versions) Class: Elevation of Privilege Summary: The SvcMoveFileInheritSecurity RPC method in StorSvc can be used to move an arbitrary file to an arbitrary location resulting in elevation of privilege. Description: I was reading Clément Rouault & Thomas Imbert excellent PacSec’s slides on ALPC+RPC issues and they highlighted the SvcMoveFileInheritSecurity method used to exploit the ALPC bug CVE-2017-11783. The function impersonates the user and calls MoveFileEx to move the file to a new destination, then reverts the impersonation and tries to reset the security descriptor of the new file so that it matches the inheritable permissions. The ALPC bug in CVE-2017-11783 has apparently been fixed but the behavior of the SvcMoveFileInheritSecurity has not been modified as far as I can tell. The main problem occurs if the call to SetNamedSecurityInfo fails, in that case the code tries to move the file back to its original location, however it does reassert the impersonation. This probably makes sense because it’s possible to have a file/directory which you can open for DELETE but without the rights to create a new file in the same directory. In the case the original move would succeed but the revert would fail. However there’s a TOCTOU issue in that the original path might have been replaced with a mount point which redirects the revert to a totally arbitrary location while running at SYSTEM. The exploit controls both the name and the contents of the file so this would be a trivial privilege escalation. It’s possible to cause SetNamedSecurityInfo to fail just by adding a Deny ACE to the file for SYSTEM. This will cause the function to get ERROR_ACCESS_DENIED and the revert will take place. By placing an oplock on the original file open we can switch in a mount point and always win the race condition. Ideally all operations should take place under user impersonation, but if that was the case there’d be no point in doing it in a SYSTEM service to begin with. Note that there’s a second issue specifically with SetNamedSecurityInfo which I’ve sent as a separate issue, just in case it gets missed. Proof of Concept: I’ve provided a PoC as a C++ project. It will abuse the SvcMoveFileInheritSecurity method to create the file test.txt in the windows folder. 1) Compile the C++ project. 2) Execute the PoC as a normal user. Expected Result: The file reversion fails trying to copy the file back to its original location. Observed Result: The file is reverted which results in the test.txt file being creating in c:\windows. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/44152.zip

Products Mentioned

Configuraton 0

Microsoft>>Windows_10 >> Version 1511

Microsoft>>Windows_10 >> Version 1607

Microsoft>>Windows_10 >> Version 1703

Microsoft>>Windows_10 >> Version 1709

Microsoft>>Windows_server_2016 >> Version -

Microsoft>>Windows_server_2016 >> Version 1709

References

https://www.exploit-db.com/exploits/44152/
Tags : exploit, x_refsource_EXPLOIT-DB
http://www.securityfocus.com/bid/102944
Tags : vdb-entry, x_refsource_BID
http://www.securitytracker.com/id/1040379
Tags : vdb-entry, x_refsource_SECTRACK