{"id":"CVE-2023-40033","aliases":["EUVD-2023-2223","GHSA-67c6-q4j4-hccg"],"status":"published","title":"Server-Side Request Forgery via Avatar upload in flarum","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.","severity":{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00504,"percentile":0.43455,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-918","CWE-98"],"published":"2023-08-16T20:34:11Z","modified":"2026-10-28T02:30:34Z","fixes":[{"ecosystem":"Packagist","package":"flarum/core","fixed_in":["1.8.0"],"sources":["ghsa","osv"]},{"ecosystem":"Packagist","package":"flarum/framework","fixed_in":["1.8.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"flarum/core","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.0"}]}]},{"source":"ghsa","ecosystem":"Packagist","package":"flarum/framework","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.0"}]}]},{"source":"osv","ecosystem":"Packagist","package":"flarum/core","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.0"}]}],"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"]},{"source":"osv","ecosystem":"Packagist","package":"flarum/framework","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.0"}]}],"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"]}],"products":[{"vendor":"flarum","product":"flarum"},{"vendor":"flarum","product":"framework"}],"references":[{"url":"https://github.com/flarum/framework/security/advisories/GHSA-67c6-q4j4-hccg","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory","web"]},{"url":"https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-40033","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-67c6-q4j4-hccg"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/40xxx/CVE-2023-40033.json","tags":["advisory"]},{"url":"https://github.com/flarum/framework","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-40033","title":"Server-Side Request Forgery via Avatar upload in flarum","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.","status":"published","published":"2023-08-16T20:34:11.445Z","modified":"2024-10-02T16:00:40.87Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:35:21.971258Z"}],"euvd":[{"id":"EUVD-2023-2223","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.","status":"published","published":"2023-08-16T20:34:11Z","modified":"2024-10-02T16:00:40Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high"}],"updated_at":"2026-11-03T00:27:58.042417Z"}],"ghsa":[{"id":"GHSA-67c6-q4j4-hccg","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","status":"published","published":"2023-08-16T21:02:52Z","modified":"2023-11-09T05:05:57Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-98","CWE-918"],"updated_at":"2026-11-02T14:37:18.40412Z"}],"nvd":[{"id":"CVE-2023-40033","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.","status":"published","published":"2023-08-16T21:15:09.987Z","modified":"2026-06-17T06:15:51.27Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high","assessor":"secondary"},{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high","assessor":"primary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:08:24.487686Z"}],"osv":[{"id":"CVE-2023-40033","title":"Server-Side Request Forgery via Avatar upload in flarum","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.","status":"published","published":"2023-08-16T20:34:11.445Z","modified":"2026-10-28T02:30:34.010833434Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:44:33.244128Z"},{"id":"GHSA-67c6-q4j4-hccg","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","status":"published","published":"2023-08-16T21:02:52Z","modified":"2026-09-10T03:49:57.375221017Z","cvss":[{"version":"3.1","score":7.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","level":"high"}],"cwes":["CWE-918","CWE-98"],"updated_at":"2026-11-02T15:46:39.266402Z"}]}}