Validación inadecuada de las credenciales de redireccionamiento de SSO permite el robo de credenciales

The primary impact of CVE-2025-59480 is the potential for unauthorized access to user accounts within Mattermost. An attacker controlling a malicious Mattermost instance or positioned as an on-path attacker can craft a malicious token-in-URL response. When a user authenticates through SSO, the redirect token, which is intended to securely pass authentication information, is not properly validated. This allows the attacker to impersonate the user and gain access to their data and communication history. The blast radius extends to all users relying on SSO for authentication within the affected Mattermost Mobile Apps.

Organizations heavily reliant on SSO for Mattermost authentication are particularly at risk. Users on shared devices or those who frequently authenticate from untrusted networks are also more vulnerable. Legacy Mattermost deployments using older SSO providers or custom integrations may be at higher risk due to potential configuration issues.

• mattermost / mobile:

Get-MobileAppVersion | Where-Object {$_.Version -le '2.32.0'}

• generic web:

curl -I https://your-mattermost-instance/ | grep -i 'redirect_uri'

• generic web: Examine Mattermost server logs for unusual SSO redirect URLs or patterns.

1. 2025-11-13Disclosure

   disclosure

1. Reservado2025-10-15
2. Publicada2025-11-13
3. EPSS actualizado2026-03-23

The primary mitigation for CVE-2025-59480 is to immediately upgrade Mattermost Mobile Apps to version 2.33.0 or later. If upgrading is not immediately feasible, consider implementing temporary workarounds such as restricting access to Mattermost from untrusted networks or implementing stricter SSO configuration policies. Monitor network traffic for suspicious redirect URLs and consider using a Web Application Firewall (WAF) to filter out malicious requests. After upgrading, verify the fix by attempting an SSO login and confirming that the redirect token is properly validated.