{"cve":"CVE-2023-40033","nvd":{"published":"2023-08-16T21:15:09.987","modified":"2026-06-17T06:15:51.270","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","score":7.1},"cwes":["CWE-918"],"references":["https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570","https://github.com/flarum/framework/security/advisories/GHSA-67c6-q4j4-hccg","https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570","https://github.com/flarum/framework/security/advisories/GHSA-67c6-q4j4-hccg"],"products":["flarum:flarum"],"source":"nvd","synced_at":"2026-10-19T21:39:14.809778102+00:00"},"epss":{"cve":"CVE-2023-40033","score":0.00504,"percentile":0.43131,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}