# CVE-2021-21265: October CMS vulnerable to Potential Host Header Poisoning on misconfigured servers

Source: https://junglewise.ai/threats/cve-2021-21265-october-cms-vulnerable-to-potential-host-header-poisoning-on  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-03-10  
License: CC BY 4.0 with a link back

CVE-2021-21265 · Severity: info · Published 2021-03-10

October CMS vulnerable to Potential Host Header Poisoning on misconfigured servers

Technologies: [october/backend (Packagist)](https://junglewise.ai/threats/technologies/october-backend). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2021-21265 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-21265 being exploited in the wild.

**How severe is CVE-2021-21265?** Informational severity, published 10 March 2021.

**Which products and versions are affected?** october/backend (Packagist) ECOSYSTEM:introduced=0,fixed=1.1.2.

**Is there a fix for CVE-2021-21265?** Yes. october/backend (Packagist): upgrade to 1.1.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-21265?** Check whether you run october/backend (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- october/backend (Packagist): upgrade to 1.1.2 or later

  ```sh
  composer require october/backend:^1.1.2
  ```


## Affected products

- october/backend (Packagist) ECOSYSTEM:introduced=0,fixed=1.1.2

## Identifiers

- CVE-2021-21265
- GHSA-xhfx-hgmf-v6vp

## Related threats

- [Stored XSS by authenticated backend user with access to upload files](https://junglewise.ai/threats/cve-2020-15249-stored-xss-by-authenticated-backend-user-with-access-to-upload)
- [Privilege escalation by backend users assigned to the default "Publisher" system role](https://junglewise.ai/threats/cve-2020-15248-privilege-escalation-by-backend-users-assigned-to-the-default)
- [Stored XSS in October](https://junglewise.ai/threats/cve-2020-11083-stored-xss-in-october)
- [Cross-site Scripting in October](https://junglewise.ai/threats/cve-2020-4061-cross-site-scripting-in-october)
- [Potential CSV Injection vector in OctoberCMS](https://junglewise.ai/threats/cve-2020-5299-potential-csv-injection-vector-in-octobercms)