CVE-2021-20827 Vulnerability Analysis & Exploit Details

CVE-2021-20827
Vulnerability Scoring

7.5
/10
Very High Risk

Highly exploitable, CVE-2021-20827 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: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-20827 Details

Status: Modified

Last updated: 🕠 21 Nov 2024, 05:47 UTC
Originally published on: 🕖 24 Dec 2021, 07:15 UTC

Time between publication and last update: 1062 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:N/S:U/C:H/I:N/A:N

CVE-2021-20827 Vulnerability Summary

CVE-2021-20827: Plaintext storage of a password vulnerability in IDEC PLCs (FC6A Series MICROSmart All-in-One CPU module v2.32 and earlier, FC6A Series MICROSmart Plus CPU module v1.91 and earlier, WindLDR v8.19.1 and earlier, WindEDIT Lite v1.3.1 and earlier, and Data File Manager v2.12.1 and earlier) allows an attacker to obtain the PLC Web server user credentials from file servers, backup repositories, or ZLD files saved in SD cards. As a result, the attacker may access the PLC Web server and hijack the PLC, and manipulation of the PLC output and/or suspension of the PLC may be conducted.

Assessing the Risk of CVE-2021-20827

Access Complexity Graph

The exploitability of CVE-2021-20827 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-2021-20827

With low attack complexity and no required privileges, CVE-2021-20827 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-2021-20827, 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-2021-20827, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2021-20827 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: None
    CVE-2021-20827 poses no threat to data integrity.
  • Availability: None
    CVE-2021-20827 does not impact system availability.

Exploit Prediction Scoring System (EPSS)

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

EPSS Score: 0.149% (probability of exploit)

EPSS Percentile: 52.35% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 47.65% of others.

CVE-2021-20827 References

External References

CWE Common Weakness Enumeration

CWE-312

CAPEC Common Attack Pattern Enumeration and Classification

  • Retrieve Embedded Sensitive Data CAPEC-37 An attacker examines a target system to find sensitive data that has been embedded within it. This information can reveal confidential contents, such as account numbers or individual keys/credentials that can be used as an intermediate step in a larger attack.

Vulnerable Configurations

  • cpe:2.3:o:idec:microsmart_fc6a_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:idec:microsmart_fc6a_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:idec:microsmart_fc6a_firmware:2.32:*:*:*:*:*:*:*
    cpe:2.3:o:idec:microsmart_fc6a_firmware:2.32:*:*:*:*:*:*:*
  • cpe:2.3:h:idec:microsmart_fc6a:-:*:*:*:*:*:*:*
    cpe:2.3:h:idec:microsmart_fc6a:-:*:*:*:*:*:*:*
  • cpe:2.3:o:idec:microsmart_plus_fc6a_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:idec:microsmart_plus_fc6a_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:idec:microsmart_plus_fc6a_firmware:1.91:*:*:*:*:*:*:*
    cpe:2.3:o:idec:microsmart_plus_fc6a_firmware:1.91:*:*:*:*:*:*:*
  • cpe:2.3:h:idec:microsmart_plus_fc6a:-:*:*:*:*:*:*:*
    cpe:2.3:h:idec:microsmart_plus_fc6a:-:*:*:*:*:*:*:*

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