Vulnerability-Lookup

BDU:2026-00978 (CVE-2021-47857)

Vulnerability from fstec – Published: 2026-01-30 – Updated: 2026-01-30 – View on bdu.fstec.ru Exploit publicly available No remediation information

Title

Уязвимость поля субтитров событий календаря виртуальной обучающей среды Moodle, позволяющая нарушителю проводить межсайтовые сценарные атаки (XSS)

Summary

Уязвимость поля субтитров событий календаря виртуальной обучающей среды Moodle связана с непринятием мер по защите структуры веб-страницы. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, проводить межсайтовые сценарные атаки (XSS)

Severity

6.4 (Medium) CVSS 2.0


                      
                        AV:N/AC:L/Au:N/C:P/I:P/A:N

5.4 (Medium) CVSS 3.1


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

5.1 (Medium) CVSS 4.0


                      
                        CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

Class

Code vulnerability

Status

Potential vulnerability

Exploitation

Injection

Incidents

Being clarified

Remediation

Being clarified

CWE

CWE-79 - Непринятие мер по защите структуры веб-страницы (или \«Межсайтовая сценарная атака\»)

Aliases

CVE-2021-47857

References

2 references

URL
https://github.com/advisories/GHSA-px56-6vfj-h8xp?ysclid=mkxug07x1872998433
https://www.exploit-db.com/exploits/49714

Impacted products

1 product from 1 vendor

Vendors

Мартин Догиамас

Products

Moodle

Versions

3.10.3 (Moodle)

Product types

Network software

Mitigations

Компенсирующие меры: - анализ ограничений XSS-защиты в зависимости от используемого фреймворка и обеспечение соответствующей обработки возникающих исключительных ситуаций; - использование проверки входных данных по «белым спискам»; - использование средств межсетевого экранирования уровня веб-приложений.

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:L/Au:N/C:P/I:P/A:N",
  "CVSS 3.0": "AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
  "CVSS 4.0": "AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N",
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "\u041c\u0430\u0440\u0442\u0438\u043d \u0414\u043e\u0433\u0438\u0430\u043c\u0430\u0441",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "3.10.3 (Moodle)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u041a\u043e\u043c\u043f\u0435\u043d\u0441\u0438\u0440\u0443\u044e\u0449\u0438\u0435 \u043c\u0435\u0440\u044b:\n\n- \u0430\u043d\u0430\u043b\u0438\u0437 \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u0438\u0439 XSS-\u0437\u0430\u0449\u0438\u0442\u044b \u0432 \u0437\u0430\u0432\u0438\u0441\u0438\u043c\u043e\u0441\u0442\u0438 \u043e\u0442 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u043e\u0433\u043e \u0444\u0440\u0435\u0439\u043c\u0432\u043e\u0440\u043a\u0430 \u0438 \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u0435 \u0441\u043e\u043e\u0442\u0432\u0435\u0442\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u0439 \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u043a\u0438 \u0432\u043e\u0437\u043d\u0438\u043a\u0430\u044e\u0449\u0438\u0445 \u0438\u0441\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u044b\u0445 \u0441\u0438\u0442\u0443\u0430\u0446\u0438\u0439;\n\n- \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0438 \u0432\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445 \u043f\u043e \u00ab\u0431\u0435\u043b\u044b\u043c \u0441\u043f\u0438\u0441\u043a\u0430\u043c\u00bb;\n\n- \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432 \u043c\u0435\u0436\u0441\u0435\u0442\u0435\u0432\u043e\u0433\u043e \u044d\u043a\u0440\u0430\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u0443\u0440\u043e\u0432\u043d\u044f \u0432\u0435\u0431-\u043f\u0440\u0438\u043b\u043e\u0436\u0435\u043d\u0438\u0439.",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "25.03.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "30.01.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "30.01.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-00978",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2021-47857",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0443\u0435\u0442",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Moodle",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": null,
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u043b\u044f \u0441\u0443\u0431\u0442\u0438\u0442\u0440\u043e\u0432 \u0441\u043e\u0431\u044b\u0442\u0438\u0439 \u043a\u0430\u043b\u0435\u043d\u0434\u0430\u0440\u044f \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u043e\u0439 \u043e\u0431\u0443\u0447\u0430\u044e\u0449\u0435\u0439 \u0441\u0440\u0435\u0434\u044b Moodle, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u043f\u0440\u043e\u0432\u043e\u0434\u0438\u0442\u044c \u043c\u0435\u0436\u0441\u0430\u0439\u0442\u043e\u0432\u044b\u0435 \u0441\u0446\u0435\u043d\u0430\u0440\u043d\u044b\u0435 \u0430\u0442\u0430\u043a\u0438 (XSS)",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0421\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u0435",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u043f\u0440\u0438\u043d\u044f\u0442\u0438\u0435 \u043c\u0435\u0440 \u043f\u043e \u0437\u0430\u0449\u0438\u0442\u0435 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u044b \u0432\u0435\u0431-\u0441\u0442\u0440\u0430\u043d\u0438\u0446\u044b (\u0438\u043b\u0438 \\\u00ab\u041c\u0435\u0436\u0441\u0430\u0439\u0442\u043e\u0432\u0430\u044f \u0441\u0446\u0435\u043d\u0430\u0440\u043d\u0430\u044f \u0430\u0442\u0430\u043a\u0430\\\u00bb) (CWE-79)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u043b\u044f \u0441\u0443\u0431\u0442\u0438\u0442\u0440\u043e\u0432 \u0441\u043e\u0431\u044b\u0442\u0438\u0439 \u043a\u0430\u043b\u0435\u043d\u0434\u0430\u0440\u044f \u0432\u0438\u0440\u0442\u0443\u0430\u043b\u044c\u043d\u043e\u0439 \u043e\u0431\u0443\u0447\u0430\u044e\u0449\u0435\u0439 \u0441\u0440\u0435\u0434\u044b Moodle \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u043f\u0440\u0438\u043d\u044f\u0442\u0438\u0435\u043c \u043c\u0435\u0440 \u043f\u043e \u0437\u0430\u0449\u0438\u0442\u0435 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u044b \u0432\u0435\u0431-\u0441\u0442\u0440\u0430\u043d\u0438\u0446\u044b. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u043f\u0440\u043e\u0432\u043e\u0434\u0438\u0442\u044c \u043c\u0435\u0436\u0441\u0430\u0439\u0442\u043e\u0432\u044b\u0435 \u0441\u0446\u0435\u043d\u0430\u0440\u043d\u044b\u0435 \u0430\u0442\u0430\u043a\u0438 (XSS)",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u0418\u043d\u044a\u0435\u043a\u0446\u0438\u044f",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://github.com/advisories/GHSA-px56-6vfj-h8xp?ysclid=mkxug07x1872998433\nhttps://www.exploit-db.com/exploits/49714",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0442\u0435\u043d\u0446\u0438\u0430\u043b\u044c\u043d\u0430\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c",
  "\u0422\u0438\u043f \u041f\u041e": "\u0421\u0435\u0442\u0435\u0432\u043e\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432\u043e",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-79",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 6,4)\n\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 5,4)\n\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u043e\u0446\u0435\u043d\u043a\u0430 CVSS 4.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 5,1)"
}

CVE-2021-47857 (GCVE-0-2021-47857)

Vulnerability from cvelistv5 – Published: 2026-01-21 17:27 – Updated: 2026-03-05 01:28

Title

Moodle 3.10.3 - 'label' Persistent Cross Site Scripting

Summary

Moodle 3.10.3 contains a persistent cross-site scripting vulnerability in the calendar event subtitle field that allows attackers to inject malicious scripts. Attackers can craft a calendar event with malicious JavaScript in the subtitle track label to execute arbitrary code when users view the event.

Severity

5.1 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

7.2 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-01-22 22:09 UTC

CWE

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

Assigner

VulnCheck mitre root

References

3 references

URL	Tags
https://www.exploit-db.com/exploits/49714	exploit
https://moodle.org/	product
https://www.vulncheck.com/advisories/moodle-label…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
Moodle	Moodle	Affected: 3.10.3 cpe:2.3:a:moodle:moodle:3.10.3:::::::*

Date Public

2021-03-25 00:00

Credits

Vincent666 ibn Winnie

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47857",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-22T22:09:26.881063Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-22T22:09:37.406Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Moodle",
          "vendor": "Moodle",
          "versions": [
            {
              "status": "affected",
              "version": "3.10.3"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:moodle:moodle:3.10.3:*:*:*:*:*:*:*",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Vincent666 ibn Winnie"
        }
      ],
      "datePublic": "2021-03-25T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Moodle 3.10.3 contains a persistent cross-site scripting vulnerability in the calendar event subtitle field that allows attackers to inject malicious scripts. Attackers can craft a calendar event with malicious JavaScript in the subtitle track label to execute arbitrary code when users view the event."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.1,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-05T01:28:54.718Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "ExploitDB-49714",
          "tags": [
            "exploit"
          ],
          "url": "https://www.exploit-db.com/exploits/49714"
        },
        {
          "name": "Official Moodle Project Homepage",
          "tags": [
            "product"
          ],
          "url": "https://moodle.org/"
        },
        {
          "name": "VulnCheck Advisory: Moodle 3.10.3 - \u0027label\u0027 Persistent Cross Site Scripting",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/moodle-label-persistent-cross-site-scripting"
        }
      ],
      "title": "Moodle 3.10.3 - \u0027label\u0027 Persistent Cross Site Scripting",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2021-47857",
    "datePublished": "2026-01-21T17:27:39.382Z",
    "dateReserved": "2026-01-14T17:11:19.904Z",
    "dateUpdated": "2026-03-05T01:28:54.718Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

BDU:2026-00978 (CVE-2021-47857)

CVE-2021-47857 (GCVE-0-2021-47857)

Tags

Sightings

Nomenclature

Related by attack behaviour