TI-2023-20923 Aliases CVE-2023-40033 GHSA-67c6-q4j4-hccg

Server-Side Request Forgery via Avatar upload in flarum

LOW 32CWE-918Published 2023-08-16 · Updated 2024-10-02

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-98.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00504 43rd percentileScored 2026-11-07

Fix Fixed framework (flarum): 1.8.0flarum/core (Packagist): 1.8.0+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
flarum	framework	before 1.8.0	1.8.0	Patch available	CNA
—	flarum/core (Packagist)	before 1.8.0	1.8.0	Patch available	GHSA-67c6-q4j4-hccg
—	flarum/framework (Packagist)	before 1.8.0	1.8.0	Patch available	GHSA-67c6-q4j4-hccg

framework Vendorflarum Affected before 1.8.0 Fixed in 1.8.0 Patch available CNA
flarum/core (Packagist) Vendor— Affected before 1.8.0 Fixed in 1.8.0 Patch available GHSA-67c6-q4j4-hccg
flarum/framework (Packagist) Vendor— Affected before 1.8.0 Fixed in 1.8.0 Patch available GHSA-67c6-q4j4-hccg

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:flarum:flarum::::::::	before 1.8.0	Vulnerable	flarum

cpe:2.3:a:flarum:flarum:*:*:*:*:*:*:*:* Versions before 1.8.0 Vulnerable ·flarum

Remediation

Fix · CNA framework (flarum) Fixed in 1.8.0
Fix · GHSA-67c6-q4j4-hccg flarum/core (Packagist) Fixed in 1.8.0 Advisory →
Fix · GHSA-67c6-q4j4-hccg flarum/framework (Packagist) Fixed in 1.8.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2023-40033
2026-10-03 Alias added: GHSA-67c6-q4j4-hccg

References

Patch 1

https://github.com/flarum/framework/commit/d1059c1cc79fe61f9538f3da55e8f42abbede570

Advisory 2

Other 1

https://github.com/flarum/framework

TI-2021-12339 XSS vulnerability with translator CVSS 3.1CRITICAL 10.0
TI-2023-08736 Post mentions can be used to read any post on the forum without access control CVSS 3.1HIGH 7.7
TI-2025-20573 Flarum Vulnerable to Session Hijacking via Authoritative Subdomain Cookie Overwrite CVSS 3.1MEDIUM 6.8
TI-2022-20279 Cross site scripting vulnerability with discussion titles in flarum CVSS 3.1CRITICAL 9.0
TI-2019-09878 Flarum before 0.1.0-beta.9 allows CSRF against all POST endpoints, as demonstrated by changing admin settings. CVSS 3.0HIGH 8.8
TI-2019-08604 User/Command/ConfirmEmailHandler.php in Flarum before 0.1.0-beta.8 mishandles invalidation of user email tokens. CVSS 3.0HIGH 7.5

See all 11 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences