CVE-2021-40415 Vulnerability Analysis & Exploit Details

CVE-2021-40415
Vulnerability Scoring

6.5
/10
High Risk

If left unpatched, CVE-2021-40415 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: Low
    Some privileges are necessary to exploit the vulnerability.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-40415 Details

Status: Modified

Last updated: 🕕 21 Nov 2024, 06:24 UTC
Originally published on: 🕗 28 Jan 2022, 20:15 UTC

Time between publication and last update: 1027 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

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

CVE-2021-40415 Vulnerability Summary

CVE-2021-40415: An incorrect default permission vulnerability exists in the cgiserver.cgi cgi_check_ability functionality of reolink RLC-410W v3.0.0.136_20121102. In cgi_check_ability the Format API does not have a specific case, the user permission will default to 7. This will give non-administrative users the possibility to format the SD card and reboot the device.

Assessing the Risk of CVE-2021-40415

Access Complexity Graph

The exploitability of CVE-2021-40415 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-2021-40415

CVE-2021-40415 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-2021-40415, 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-2021-40415, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2021-40415 has no significant impact on data confidentiality.
  • Integrity: None
    CVE-2021-40415 poses no threat to data integrity.
  • Availability: High
    CVE-2021-40415 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: 0.067% (probability of exploit)

EPSS Percentile: 32.48% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 67.52000000000001% of others.

CVE-2021-40415 References

External References

CWE Common Weakness Enumeration

CWE-276

CAPEC Common Attack Pattern Enumeration and Classification

  • Accessing Functionality Not Properly Constrained by ACLs CAPEC-1 In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.
  • Directory Indexing CAPEC-127 An adversary crafts a request to a target that results in the target listing/indexing the content of a directory as output. One common method of triggering directory contents as output is to construct a request containing a path that terminates in a directory name rather than a file name since many applications are configured to provide a list of the directory's contents when such a request is received. An adversary can use this to explore the directory tree on a target as well as learn the names of files. This can often end up revealing test files, backup files, temporary files, hidden files, configuration files, user accounts, script contents, as well as naming conventions, all of which can be used by an attacker to mount additional attacks.
  • Web Server Logs Tampering CAPEC-81 Web Logs Tampering attacks involve an attacker injecting, deleting or otherwise tampering with the contents of web logs typically for the purposes of masking other malicious behavior. Additionally, writing malicious data to log files may target jobs, filters, reports, and other agents that process the logs in an asynchronous attack pattern. This pattern of attack is similar to "Log Injection-Tampering-Forging" except that in this case, the attack is targeting the logs of the web server and not the application.

Vulnerable Configurations

  • cpe:2.3:o:reolink:rlc-410w_firmware:3.0.0.136_20121102:*:*:*:*:*:*:*
    cpe:2.3:o:reolink:rlc-410w_firmware:3.0.0.136_20121102:*:*:*:*:*:*:*
  • cpe:2.3:h:reolink:rlc-410w:-:*:*:*:*:*:*:*
    cpe:2.3:h:reolink:rlc-410w:-:*:*:*:*:*:*:*

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