CVE-2021-1691 Vulnerability Analysis & Exploit Details

CVE-2021-1691
Vulnerability Scoring

7.7
/10
Very High Risk

Highly exploitable, CVE-2021-1691 poses a critical security risk that could lead to severe breaches.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • Privileges Required: Low
    Some privileges are necessary to exploit the vulnerability.
  • Scope: Changed
    Successful exploitation can impact components beyond the vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-1691 Details

Status: Modified

Last updated: 🕠 21 Nov 2024, 05:44 UTC
Originally published on: 🕗 12 Jan 2021, 20:15 UTC

Time between publication and last update: 1408 days

CVSS Release: version 3

CVSS3 Source

secure@microsoft.com

CVSS3 Type

Secondary

CVSS3 Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CVE-2021-1691 Vulnerability Summary

CVE-2021-1691: Windows Hyper-V Denial of Service Vulnerability

Assessing the Risk of CVE-2021-1691

Access Complexity Graph

The exploitability of CVE-2021-1691 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2021-1691

CVE-2021-1691 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2021-1691, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2021-1691, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2021-1691 has no significant impact on data confidentiality.
  • Integrity: None
    CVE-2021-1691 poses no threat to data integrity.
  • Availability: High
    CVE-2021-1691 can disrupt system operations, potentially causing complete denial of service (DoS).

Exploit Prediction Scoring System (EPSS)

The EPSS score estimates the probability that this vulnerability will be exploited in the near future.

EPSS Score: 0.208% (probability of exploit)

EPSS Percentile: 59.34% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 40.66% of others.

CVE-2021-1691 References

External References

CWE Common Weakness Enumeration

NVD-CWE-noinfo

Vulnerable Configurations

  • cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_server_2016:20h2:*:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:*
  • cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*
    cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:*

Protect Your Infrastructure against CVE-2021-1691: Combat Critical CVE Threats

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