CVE-2021-22958

CriticalCVSS 9.8/10Last modified Jun 17, 2026

Description

A Server-Side Request Forgery vulnerability was found in concrete5 < 8.5.5 that allowed a decimal notation encoded IP address to bypass the limitations in place for localhost allowing interaction with local services. Impact can vary depending on services exposed.CVSSv2.0 AV:A/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N

Metrics

CVSS 3.1 9.8/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness enumeration

CWE-918

Affected software

Vendor	Product	Versions
n/a	https://github.com/concrete5/concrete5	Fixed in 8.5.5

References

https://documentation.concretecms.org/developers/introduction/version-history/855-release-notesRelease Notes, Vendor Advisory
https://hackerone.com/reports/863221Issue Tracking, Permissions Required, Third Party Advisory
https://documentation.concretecms.org/developers/introduction/version-history/855-release-notesRelease Notes, Vendor Advisory
https://hackerone.com/reports/863221Issue Tracking, Permissions Required, Third Party Advisory

Timeline

Published: Oct 7, 2021
Last modified: Jun 17, 2026
NVD status: Modified

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