{"id":"CVE-2023-40033","summary":"Server-Side Request Forgery via Avatar upload in flarum","details":"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.","aliases":["GHSA-67c6-q4j4-hccg"],"modified":"2026-08-12T03:51:46.596885511Z","published":"2023-08-16T20:34:11.445Z","database_specific":{"cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/40xxx/CVE-2023-40033.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/40xxx/CVE-2023-40033.json"},{"type":"ADVISORY","url":"https://github.com/flarum/framework/security/advisories/GHSA-67c6-q4j4-hccg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-40033"},{"type":"FIX","url":"https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/flarum/framework","events":[{"introduced":"0"},{"fixed":"d27f9525847212fedd555ed165a2eb80bca17328"},{"fixed":"d1059c1cc79fe61f9538f3da55e8f42abbede570"}],"database_specific":{"cpe":"cpe:2.3:a:flarum:flarum:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.8.0"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v1.7.1","v1.7.0","v1.6.1","v1.6.0","v1.5.0","v1.4.0","v1.3.1","v1.3.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-40033.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N"}]}