CVE-2023-40033: SSRF

First published: Wed Aug 16 2023(Updated: )

## Impact The Flarum forum software is affected by a vulnerability that allows an attacker to conduct a Blind SSRF attack or disclose any file on the server, even with a basic user account on any Flarum forum. By uploading a file containing a URL and spoofing the MIME type, an attacker can manipulate the application to execute unintended actions. The vulnerability is due to the behavior of the `intervention/image` package, which attempts to interpret the supplied file contents as a URL, which then fetches its contents. This allows an attacker to exploit the vulnerability to perform SSRF attacks, disclose local file contents, or conduct a blind oracle attack. ### Patches This has been patched in Flarum **v1.8**. ## Workarounds As a temporary workaround for the SSRF aspect of the vulnerability, one can disable PHP's `allow_url_fopen` which will prevent the fetching of external files via URLs. ### Credits Adam Kues - [Assetnote](https://assetnote.io/)

Credit: security-advisories@github.com security-advisories@github.com security-advisories@github.com

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• collector/github-advisory
• alias/GHSA-67c6-q4j4-hccg
• alias/CVE-2023-40033
• collector/github-advisory-latest
• collector/nvd-api
• collector/nvd-cve
• collector/nvd-index
• agent/author
• agent/description
• agent/event
• agent/first-publish-date
• agent/last-modified-date
• agent/references
• agent/remedy
• agent/severity
• agent/softwarecombine
• agent/tags
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• agent/weakness
• package-manager/composer
• vendor/flarum
• canonical/flarum flarum