Executive brief
ash_admin is a web-based administration interface used to manage Ash Framework applications. An attacker who controls a sibling subdomain can forge cookies that override legitimate session state, allowing them to hijack an administrator's session and impersonate them with different permissions, tenants, or authorization modes. This could lead to unauthorized administrative access and data compromise.
Technical details
The vulnerability is a cookie validation failure (CWE-347) in ash_admin's client-side JavaScript. The code reads session-state cookies by matching cookie names against document.cookie using an unanchored regular expression (new RegExp(name + "=([^;]+)")), which matches any cookie whose name merely ends with the requested name. Since cookies are shared across a registrable domain via the Domain attribute, a compromised sibling subdomain can set shadowing cookies (e.g., "xactor_authorizing" to match "actor_authorizing") that flow unvalidated into the LiveSocket connect parameters. No authentication is required; the attack vector is network-based and depends only on subdomain compromise. The fix validates cookie names by exact equality rather than substring matching.
Affected products
- ash-project ash_admin 0.9.1 to before 1.3.1
Timeline
- 2026-08-31: disclosed