{"id":"GHSA-67c6-q4j4-hccg","aliases":["CVE-2023-40033"],"title":"Flarum vulnerable to LFI and Blind SSRF via Avatar upload","description":"## Impact\nThe 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.\n\n### Patches\nThis has been patched in Flarum **v1.8**.\n\n## Workarounds\nAs 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.\n\n### Credits\nAdam Kues - [Assetnote](https://assetnote.io/)\n","severity":"high","score":7.1,"published":"2023-08-16T21:02:52.000Z","modified":"2026-09-10T03:49:57.375Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Packagist","name":"flarum/core","ranges":[{"events":[{"introduced":"0"},{"fixed":"1.8.0"}],"type":"ECOSYSTEM"}],"versions":["v0.1.0-beta","v0.1.0-beta.10","v0.1.0-beta.11","v0.1.0-beta.11.1","v0.1.0-beta.12","v0.1.0-beta.13","v0.1.0-beta.14","v0.1.0-beta.14.1","v0.1.0-beta.15","v0.1.0-beta.16","v0.1.0-beta.2","v0.1.0-beta.3","v0.1.0-beta.4","v0.1.0-beta.5","v0.1.0-beta.6","v0.1.0-beta.7","v0.1.0-beta.7.1","v0.1.0-beta.7.2","v0.1.0-beta.8","v0.1.0-beta.8.1","v0.1.0-beta.8.2","v0.1.0-beta.9","v1.0.0","v1.0.1","v1.0.2","v1.0.3","v1.0.4","v1.1.0","v1.1.1","v1.2.0","v1.2.1","v1.3.0","v1.3.1","v1.4.0","v1.4.1","v1.5.0","v1.6.0","v1.6.1","v1.6.2","v1.6.3","v1.7.0","v1.7.1","v1.7.2"],"fixed":["1.8.0"]},{"ecosystem":"Packagist","name":"flarum/framework","ranges":[{"events":[{"introduced":"0"},{"fixed":"1.8.0"}],"type":"ECOSYSTEM"}],"versions":["v0.1.0-beta","v0.1.0-beta.10","v0.1.0-beta.11","v0.1.0-beta.11.1","v0.1.0-beta.12","v0.1.0-beta.13","v0.1.0-beta.14","v0.1.0-beta.14.1","v0.1.0-beta.15","v0.1.0-beta.16","v0.1.0-beta.2","v0.1.0-beta.3","v0.1.0-beta.4","v0.1.0-beta.5","v0.1.0-beta.6","v0.1.0-beta.7","v0.1.0-beta.7.1","v0.1.0-beta.7.2","v0.1.0-beta.8","v0.1.0-beta.8.1","v0.1.0-beta.8.2","v0.1.0-beta.9","v1.0.0","v1.0.1","v1.0.2","v1.0.3","v1.0.4","v1.1.0","v1.1.1","v1.2.0","v1.2.1","v1.3.0","v1.3.1","v1.4.0","v1.5.0","v1.6.0","v1.6.1","v1.6.2","v1.6.3","v1.7.0","v1.7.1"],"fixed":["1.8.0"]}],"references":["https://github.com/flarum/framework/security/advisories/GHSA-67c6-q4j4-hccg","https://nvd.nist.gov/vuln/detail/CVE-2023-40033","https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570","https://github.com/flarum/framework"],"sources":[{"name":"OSV","id":"GHSA-67c6-q4j4-hccg","modified":"2026-09-10T03:49:57.375221017Z","url":"https://osv.dev/vulnerability/GHSA-67c6-q4j4-hccg"}],"assessments":[{"source":"OSV","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","score":7.1}]}