CVE-2021-1821 Vulnerability Analysis & Exploit Details

CVE-2021-1821
Vulnerability Scoring

6.5
/10
High Risk

If left unpatched, CVE-2021-1821 could lead to major system disruptions or data loss.

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: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: Required
    User interaction is necessary for successful exploitation.

CVE-2021-1821 Details

Status: Modified

Last updated: 🕠 21 Nov 2024, 05:45 UTC
Originally published on: 🕖 28 Oct 2021, 19:15 UTC

Time between publication and last update: 1119 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

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

CVE-2021-1821 Vulnerability Summary

CVE-2021-1821: A logic issue was addressed with improved state management. This issue is fixed in watchOS 7.6, macOS Big Sur 11.5. Visiting a maliciously crafted webpage may lead to a system denial of service.

Assessing the Risk of CVE-2021-1821

Access Complexity Graph

The exploitability of CVE-2021-1821 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-2021-1821

With low attack complexity and no required privileges, CVE-2021-1821 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.

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-2021-1821, 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-2021-1821, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2021-1821 has no significant impact on data confidentiality.
  • Integrity: None
    CVE-2021-1821 poses no threat to data integrity.
  • Availability: High
    CVE-2021-1821 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: 0.124% (probability of exploit)

EPSS Percentile: 48.32% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 51.68% of others.

CVE-2021-1821 References

External References

CWE Common Weakness Enumeration

NVD-CWE-noinfo

Vulnerable Configurations

  • cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:1.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:1.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:7.5.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:7.5.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:7.6:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:7.6:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:7.6.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:7.6.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:8.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:8.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:8.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:8.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:8.5:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:8.5:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:8.6:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:8.6:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:9:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:9:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:9.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:9.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:10.15.7:supplemental_update:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:10.15.7:supplemental_update:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.1.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.1.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.2.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.2.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.3.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.3.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:macos:11.4:*:*:*:*:*:*:*
    cpe:2.3:o:apple:macos:11.4:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:-:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:-:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:1.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:1.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:1.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:1.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.2.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.2.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:2.2.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:2.2.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.1.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.1.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.1.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.1.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.2.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.2.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:3.2.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:3.2.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.2.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.2.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.3.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.3.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:4.3.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:4.3.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.1.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.1.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.1.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.1.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.1.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.1.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.2.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.2.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.3.4:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.3.4:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.3.7:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.3.7:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:5.3.9:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:5.3.9:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.0.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.0.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.0.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.0.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.1.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.1.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.1.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.1.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.1.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.1.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.2.5:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.2.5:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.2.6:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.2.6:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.2.8:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.2.8:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:6.2.9:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:6.2.9:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.0:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.0:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.3.2:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.3.2:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.3.3:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.3.3:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.4:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.4:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.4.1:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.4.1:*:*:*:*:*:*:*
  • cpe:2.3:o:apple:watchos:7.5:*:*:*:*:*:*:*
    cpe:2.3:o:apple:watchos:7.5:*:*:*:*:*:*:*

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