CVE-2023-40033 Server-Side Request Forgery via Avatar upload in flarum
Attackers can perform SSRF or disclose local files by uploading crafted avatars, impacting confidentiality and server security.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-40033?
CVE-2023-40033 is a high-severity server-side request forgery vulnerability in flarum framework, published on 16 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Flarum is an open source forum software. Flarum is affected by a vulnerability that allows an attacker to conduct a Blind Server-Side Request Forgery (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. This has been patched in Flarum version 1.8.0. Users are advised to upgrade. Users unable to upgrade may disable PHP's `allow_url_fopen` which will prevent the fetching of external files via URLs as a temporary workaround for the SSRF aspect of the vulnerability.
Weakness: CWE-918
Which versions are affected by CVE-2023-40033?
4 open source packages ship an affected version, including flarum/framework and flarum/core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
flarum/framework Packagist | All versions | 1.8.0 |
flarum/framework Packagist | All versions | 1.8.0 |
flarum/core Packagist | All versions | 1.8.0 |
flarum/core Packagist | All versions | 1.8.0 |
Products include Flarum Flarum.
How do I fix CVE-2023-40033?
Upgrade flarum/framework to 1.8.0 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2023-40033 being exploited?
There is no known exploitation of CVE-2023-40033 in the wild and no public exploit code.
Other vulnerabilities in flarum framework
- CVE-2021-32671 XSS vulnerability with translator
- CVE-2022-41938 Cross site scripting vulnerability with discussion titles in flarum
- CVE-2019-13183 Cross-site request forgery in n/a
- CVE-2023-22487 Post mentions can be used to read any post on the forum without access control
- CVE-2019-11514 Flarum mishandles invalidation of user email tokens
Sources
Also known as GHSA-67c6-q4j4-hccg.