Vulnerability-Lookup

BDU:2021-04333 (CVE-2021-26084)

Vulnerability from fstec – Published: 2021-09-02 – Updated: 2025-08-18 – View on bdu.fstec.ru Exploit publicly available Yes Fixed

Title

Уязвимость веб-сервера Atlassian Confluence Server и дата центра Confluence Data Center, связанная с недостатками процедуры нейтрализации особых элементов в выходных данных, используемых входящим компонентом, позволяющая нарушителю выполнить произвольный код

Summary

Уязвимость веб-сервера Atlassian Confluence Server и дата центра Confluence Data Center связана с недостатками процедуры нейтрализации особых элементов в выходных данных, используемых входящим компонентом. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, выполнить произвольный код с помощью специально сформированного OGNL выражения

Severity

10.0 (High) CVSS 2.0


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

9.8 (Critical) CVSS 3.1


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

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Injection

Incidents

Yes

Remediation

Software update

CWE

CWE-74 - Неверная нейтрализация особых элементов в выходных данных, используемых входящим компонентом («инъекция»)

Aliases

CVE-2021-26084

References

7 references

URL
https://nvd.nist.gov/vuln/detail/CVE-2021-26084#range-6898374
https://jira.atlassian.com/browse/CONFSERVER-67940
https://github.com/projectdiscovery/nuclei-templates/pull/2529/files
https://confluence.atlassian.com/doc/confluence-security-advisory-2021-08-25-10…
https://github.com/httpvoid/writeups/blob/main/Confluence-RCE.md
http://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL…
https://www.cisa.gov/sites/default/files/csv/known_exploited_vulnerabilities.csv

Impacted products

2 products from 1 vendor

Vendors

Atlassian

Products

Confluence Server, Jira Data Center

Versions

до 6.13.23 (Confluence Server), от 6.14.0 до 7.4.11 (Confluence Server), от 7.12.0 до 7.12.5 (Confluence Server), от 7.5.0 до 7.11.6 (Confluence Server), до 6.13.23 (Jira Data Center), от 6.14.0 до 7.4.11 (Jira Data Center), от 7.5.0 до 7.11.6 (Jira Data Center), от 7.12.0 до 7.12.5 (Jira Data Center)

Product types

Application software

Mitigations

Обновление программного обеспечения до актуальной версии или использовать следующие компенсирующие меры: 1) В настройках системы перейти во вкладку «Управление пользователями», открыть пункт «Параметры регистрации пользователей» и отключить параметр «Разрешить людям регистрироваться для создания своей учетной записи».

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
  "CVSS 3.0": "AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "CVSS 4.0": null,
  "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": "Atlassian",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "\u0434\u043e 6.13.23 (Confluence Server), \u043e\u0442 6.14.0 \u0434\u043e 7.4.11 (Confluence Server), \u043e\u0442 7.12.0 \u0434\u043e 7.12.5 (Confluence Server), \u043e\u0442 7.5.0 \u0434\u043e 7.11.6 (Confluence Server), \u0434\u043e 6.13.23 (Jira Data Center), \u043e\u0442 6.14.0 \u0434\u043e 7.4.11 (Jira Data Center), \u043e\u0442 7.5.0 \u0434\u043e 7.11.6 (Jira Data Center), \u043e\u0442 7.12.0 \u0434\u043e 7.12.5 (Jira Data Center)",
  "\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": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f \u0434\u043e \u0430\u043a\u0442\u0443\u0430\u043b\u044c\u043d\u043e\u0439 \u0432\u0435\u0440\u0441\u0438\u0438 \u0438\u043b\u0438 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u044c \u0441\u043b\u0435\u0434\u0443\u044e\u0449\u0438\u0435 \u043a\u043e\u043c\u043f\u0435\u043d\u0441\u0438\u0440\u0443\u044e\u0449\u0438\u0435 \u043c\u0435\u0440\u044b:\n1) \u0412 \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0430\u0445 \u0441\u0438\u0441\u0442\u0435\u043c\u044b \u043f\u0435\u0440\u0435\u0439\u0442\u0438 \u0432\u043e \u0432\u043a\u043b\u0430\u0434\u043a\u0443 \u00ab\u0423\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044f\u043c\u0438\u00bb, \u043e\u0442\u043a\u0440\u044b\u0442\u044c \u043f\u0443\u043d\u043a\u0442 \u00ab\u041f\u0430\u0440\u0430\u043c\u0435\u0442\u0440\u044b \u0440\u0435\u0433\u0438\u0441\u0442\u0440\u0430\u0446\u0438\u0438 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u0435\u0439\u00bb \u0438 \u043e\u0442\u043a\u043b\u044e\u0447\u0438\u0442\u044c \u043f\u0430\u0440\u0430\u043c\u0435\u0442\u0440 \u00ab\u0420\u0430\u0437\u0440\u0435\u0448\u0438\u0442\u044c \u043b\u044e\u0434\u044f\u043c \u0440\u0435\u0433\u0438\u0441\u0442\u0440\u0438\u0440\u043e\u0432\u0430\u0442\u044c\u0441\u044f \u0434\u043b\u044f \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044f \u0441\u0432\u043e\u0435\u0439 \u0443\u0447\u0435\u0442\u043d\u043e\u0439 \u0437\u0430\u043f\u0438\u0441\u0438\u00bb.",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "27.07.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "18.08.2025",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "02.09.2021",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2021-04333",
  "\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-2021-26084",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\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": "Confluence Server, Jira Data Center",
  "\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 \u0432\u0435\u0431-\u0441\u0435\u0440\u0432\u0435\u0440\u0430 Atlassian Confluence Server \u0438 \u0434\u0430\u0442\u0430 \u0446\u0435\u043d\u0442\u0440\u0430 Confluence Data Center, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u0430\u044f \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043a\u0430\u043c\u0438 \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u044b \u043d\u0435\u0439\u0442\u0440\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043e\u0441\u043e\u0431\u044b\u0445 \u044d\u043b\u0435\u043c\u0435\u043d\u0442\u043e\u0432 \u0432 \u0432\u044b\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0432\u0445\u043e\u0434\u044f\u0449\u0438\u043c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u043e\u043c, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u043f\u043e\u043b\u043d\u0438\u0442\u044c \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u043b\u044c\u043d\u044b\u0439 \u043a\u043e\u0434",
  "\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\u0432\u0435\u0440\u043d\u0430\u044f \u043d\u0435\u0439\u0442\u0440\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u044f \u043e\u0441\u043e\u0431\u044b\u0445 \u044d\u043b\u0435\u043c\u0435\u043d\u0442\u043e\u0432 \u0432 \u0432\u044b\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0432\u0445\u043e\u0434\u044f\u0449\u0438\u043c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u043e\u043c (\u00ab\u0438\u043d\u044a\u0435\u043a\u0446\u0438\u044f\u00bb) (CWE-74)",
  "\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 \u0432\u0435\u0431-\u0441\u0435\u0440\u0432\u0435\u0440\u0430 Atlassian Confluence Server \u0438 \u0434\u0430\u0442\u0430 \u0446\u0435\u043d\u0442\u0440\u0430 Confluence Data Center \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043a\u0430\u043c\u0438 \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u044b \u043d\u0435\u0439\u0442\u0440\u0430\u043b\u0438\u0437\u0430\u0446\u0438\u0438 \u043e\u0441\u043e\u0431\u044b\u0445 \u044d\u043b\u0435\u043c\u0435\u043d\u0442\u043e\u0432 \u0432 \u0432\u044b\u0445\u043e\u0434\u043d\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0432\u0445\u043e\u0434\u044f\u0449\u0438\u043c \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u043e\u043c. \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, \u0432\u044b\u043f\u043e\u043b\u043d\u0438\u0442\u044c \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u043b\u044c\u043d\u044b\u0439 \u043a\u043e\u0434 \u0441 \u043f\u043e\u043c\u043e\u0449\u044c\u044e \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u0441\u0444\u043e\u0440\u043c\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u0433\u043e OGNL \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u044f",
  "\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",
  "\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": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\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://nvd.nist.gov/vuln/detail/CVE-2021-26084#range-6898374\nhttps://jira.atlassian.com/browse/CONFSERVER-67940\nhttps://github.com/projectdiscovery/nuclei-templates/pull/2529/files\nhttps://confluence.atlassian.com/doc/confluence-security-advisory-2021-08-25-1077906215.html\nhttps://github.com/httpvoid/writeups/blob/main/Confluence-RCE.md\nhttp://packetstormsecurity.com/files/167449/Atlassian-Confluence-Namespace-OGNL-Injection.html\nhttps://www.cisa.gov/sites/default/files/csv/known_exploited_vulnerabilities.csv",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041f\u0440\u0438\u043a\u043b\u0430\u0434\u043d\u043e\u0435 \u041f\u041e \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-74",
  "\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": "\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\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 10)\n\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\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 9,8)"
}

CVE-2021-26084 (GCVE-0-2021-26084)

Vulnerability from cvelistv5 – Published: 2021-08-30 06:30 – Updated: 2025-12-16 18:04

Summary

In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attacker to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23, from version 6.14.0 before 7.4.11, from version 7.5.0 before 7.11.6, and from version 7.12.0 before 7.12.5.

Severity

9.8 (Critical)


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

SSVC

Exploitation: active Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-12-16 18:01 UTC

CWE

Remote Code Execution
CWE-917 - Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')

Assigner

atlassian mitre root

References

3 references

URL	Tags
https://jira.atlassian.com/browse/CONFSERVER-67940	x_refsource_MISC
http://packetstormsecurity.com/files/167449/Atlas…	x_refsource_MISC
https://www.cisa.gov/known-exploited-vulnerabilit…	government-resource

Impacted products

2 products

Vendor	Product	Version
Atlassian	Confluence Server	Affected: unspecified , < 6.13.23 (custom) Affected: 6.14.0 , < unspecified (custom) Affected: unspecified , < 7.4.11 (custom) Affected: 7.5.0 , < unspecified (custom) Affected: unspecified , < 7.11.6 (custom) Affected: 7.12.0 , < unspecified (custom) Affected: unspecified , < 7.12.5 (custom)
Atlassian	Confluence Data Center	Affected: unspecified , < 6.13.23 (custom) Affected: 6.14.0 , < unspecified (custom) Affected: unspecified , < 7.4.11 (custom) Affected: 7.5.0 , < unspecified (custom) Affected: unspecified , < 7.11.6 (custom) Affected: 7.12.0 , < unspecified (custom) Affected: unspecified , < 7.12.5 (custom)

Date Public

2021-08-10 00:00

Show details on NVD website

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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.