Vulnerability Monitor

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CVE-2021-21265

October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. In October before version 1.1.2, when running on poorly configured servers (i.e. the server routes any request, regardless of the HOST header to an October CMS instance) the potential exists for Host Header Poisoning attacks to succeed. This has been addressed in version 1.1.2 by adding a feature to allow a set of trusted hosts to be specified in the application. As a workaround one may set the configuration setting cms.linkPolicy to force.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.8, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts integrity (unauthorized modifications), for affected systems. Impacting 1 product from octobercms organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2021-03-10T22:15:12.057

Last Modified

2025-05-30T00:15:20.330

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.8 (MEDIUM)

CVSSv2 Vector

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

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

8.6

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-644

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	octobercms	october	< 1.1.2	Yes

References

https://github.com/octobercms/library/commit/f29865ae3db7a03be7c49294cd93980ec457f10d ([email protected])
https://github.com/octobercms/library/commit/f86fcbcd066d6f8b939e8fe897409d152b11c3c6 Patch, Third Party Advisory ([email protected])
https://github.com/octobercms/october/commit/555ab61f2313f45d7d5d138656420ead536c5d30 ([email protected])
https://github.com/octobercms/october/commit/f638d3f78cfe91d7f6658820f9d5e424306a3db0 Patch, Third Party Advisory ([email protected])
https://github.com/octobercms/october/security/advisories/GHSA-xhfx-hgmf-v6vp Patch, Third Party Advisory ([email protected])
https://packagist.org/packages/october/backend ([email protected])
https://github.com/octobercms/library/commit/f86fcbcd066d6f8b939e8fe897409d152b11c3c6 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/octobercms/october/commit/f638d3f78cfe91d7f6658820f9d5e424306a3db0 Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/octobercms/october/security/advisories/GHSA-xhfx-hgmf-v6vp Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For octobercms's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.