BitLocker Security Feature Bypass Vulnerability

CVE-2018-8566

Security Vulnerability

Released: Nov 13, 2018

Assigning CNA: Microsoft

CVE.org link: CVE-2018-8566

Impact: Security Feature Bypass

Max Severity: Important

CVSS Source: Microsoft

Vector String: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Metrics: CVSS:3.1 4.6 / 4.6

Metric

Value

Base score metrics(8)

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible. The Base Score increases the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable component.

Physical

The attack requires the attacker to physically touch or manipulate the vulnerable component. Physical interaction may be brief or persistent.

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Such conditions may require the collection of more information about the target or computational exceptions. The assessment of this metric excludes any requirements for user interaction in order to exploit the vulnerability. If a specific configuration is required for an attack to succeed, the Base metrics should be scored assuming the vulnerable component is in that configuration.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

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

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise the vulnerable component. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.

None

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

Scope

Does a successful attack impact a component other than the vulnerable component? If so, the Base Score increases and the Confidentiality, Integrity and Authentication metrics should be scored relative to the impacted component.

Unchanged

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

Confidentiality

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.

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.

Integrity

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

None

There is no loss of integrity within the impacted component.

Availability

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. It refers to the loss of availability of the impacted component itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of an impacted component.

None

There is no impact to availability within the impacted component.

Please see Common Vulnerability Scoring System for more information on the definition of these metrics.

Executive Summary

A security feature bypass vulnerability exists when Windows improperly suspends BitLocker Device Encryption. An attacker with physical access to a powered off system could exploit this vulnerability to gain access to encrypted data.

To exploit the vulnerability, an attacker must gain physical access to the target system prior to the next system reboot.

The security update fixes the vulnerability by ensuring Windows resumes BitLocker Device Encryption.

Exploitability

The following table provides an exploitability assessment for this vulnerability at the time of original publication.

Publicly disclosed: Yes
Exploited: No
Exploitability assessment: Exploitation Less Likely

FAQ

Is CVE-2018-8566 related to Microsoft Security Advisory ADV180028 - Guidance for configuring BitLocker to enforce software encryption?

CVE-2018-8566 is not related to Microsoft Security Advisory ADV180028. Customers who install the updates listed in CVE-2018-8566 will also need to review the guidance in Security Advisory ADV180028 regarding self-encrypting drives.

Acknowledgements

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information.

Security Updates

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle.

Release date Descending

Release date

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Platform

Impact

Max Severity

Article

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Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

version

revisionDate

description

1.0

Nov 13, 2018

Information published.

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