Security Vulnerability CVE-2021-26829 - Complete Analysis and Details
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CVE-2021-26829

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This is a free service offered by Red Hot Cyber to the community. It allows you to view, on a single page, information about a single CVE from the National Vulnerability Database (NVD) and the National Institute of Standards and Technology (NIST) of the United States of America, the Forum of Incident Response and Security Teams (FIRST) regarding the EPSS score and percentile, data from the KEV catalog of the Cybersecurity and Infrastructure Security Agency (CISA), as well as selected resources from Red Hot Cyber and other international sources.

National Vulnerability Database Information

Description: OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows stored XSS via system_settings.shtm.

CVSS Base Score: 5.4 (v3.1)

The **CVSS Base Score** is a score from **0 to 10** that represents the intrinsic severity of a vulnerability. A higher score indicates greater severity.

Value
0.02.55.07.510.0
Published on: 06/11/2021 12:15:12
Last modified: 12/01/2025 15:23:18
NIST: CVE source from the National Vulnerability Database (NVD)

CVSS Metrics Details

  • Base Severity: MEDIUM
  • Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
  • Attack Vector: NETWORK
  • Attack Complexity: LOW
  • Privileges Required: LOW
  • User Interaction: REQUIRED
  • Scope: CHANGED
  • Confidentiality Impact: LOW
  • Integrity Impact: LOW
  • Availability Impact: NONE

Common Weakness Enumeration (CWE)

Database CWE: v4.18

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') ↗

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Fonte: MITRE CWE


FIRST Information

EPSS Score: 0.3540

The **EPSS (Exploit Prediction Scoring System)** is a score from **0 to 1** that indicates the **probability** that a vulnerability will be exploited in the real world in the next 30 days. A higher value indicates a greater likelihood of exploitation.

Value
0.00.250.50.751.0

Percentile: 0.9688

The **Percentile** indicates how much higher this vulnerability's EPSS score is compared to all other vulnerabilities in the EPSS database. For example, a percentile of 0.90 (90%) means that 90% of vulnerabilities have an EPSS score equal to or lower than the current one.

Value
0.00.250.50.751.0

*Data updated as of: 2025-12-11


CISA Information (Known Exploited Vulnerabilities)

The **CISA KEV Catalog** lists vulnerabilities that have been **actively exploited in the real world**. If a CVE is present in this catalog, it indicates that the threat is immediate and mitigation should be a top priority.

CVE **CVE-2021-26829** **IS PRESENT** in the CISA KEV Catalog!

  • Vulnerability Name: OpenPLC ScadaBR Cross-site Scripting Vulnerability
  • Short Description: OpenPLC ScadaBR contains a cross-site scripting vulnerability via system_settings.shtm.
  • Date Added to KEV: 11/28/2025
  • Vendor/Product: OpenPLC / ScadaBR
  • Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
  • Due Date: 12/19/2025

Articles published on Red Hot Cyber


NVD References

Exploit PoC from GitHub

No results found on GitHub for this CVE.