CVE-2025-27794 (GCVE-0-2025-27794)

Vulnerability from cvelistv5 – Published: 2025-03-12 14:00 – Updated: 2025-03-12 15:29
VLAI
Title
Flarum Vulnerable to Session Hijacking via Authoritative Subdomain Cookie Overwrite
Summary
Flarum is open-source forum software. A session hijacking vulnerability exists in versions prior to 1.8.10 when an attacker-controlled authoritative subdomain under a parent domain (e.g., `subdomain.host.com`) sets cookies scoped to the parent domain (`.host.com`). This allows session token replacement for applications hosted on sibling subdomains (e.g., `community.host.com`) if session tokens aren't rotated post-authentication. Key Constraints are that the attacker must control any subdomain under the parent domain (e.g., `evil.host.com` or `x.y.host.com`), and the parent domain must not be on the Public Suffix List. Due to non-existent session token rotation after authenticating we can theoretically reproduce the vulnerability by using browser dev tools, but due to the browser's security measures this does not seem to be exploitable as described. Version 1.8.10 contains a patch for the issue.
Severity
6.8 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-03-12 15:26 UTC
CWE
  • CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7843 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
flarum framework Affected: < 1.8.10
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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