Overview
The cybersecurity vulnerability CVE-2025-27939 exposes an alarming issue where a malicious actor can potentially alter the registered email addresses of other users, thereby taking over their accounts. This vulnerability is a major concern for all systems and organizations that rely on email-based authentication. It poses a high risk as it can lead to unauthorized access, compromise of user accounts, and potential data leakage.
Vulnerability Summary
CVE ID: CVE-2025-27939
Severity: High (7.5 CVSS)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and potential data leakage due to unauthorized account takeover.
Affected Products
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Product | Affected Versions
[Product A] | [All versions prior to 3.1.5]
[Product B] | [All versions prior to 2.0.4]
How the Exploit Works
The exploit takes advantage of a vulnerability in the system’s email address verification and updating process. The attacker sends a malicious request to the server, manipulating the system into changing the email address associated with a user account. This allows the attacker to take over the account and gain unauthorized access to system resources and data.
Conceptual Example Code
Below is a conceptual example of an HTTP request that could be used to exploit this vulnerability:
POST /user/update_email HTTP/1.1
Host: target.example.com
Content-Type: application/json
Authorization: Bearer [Attacker's token]
{ "user_id": "target_user_id", "new_email": "attacker@example.com" }In this example, the attacker uses their valid session token to send a request to the `update_email` endpoint. The `user_id` and `new_email` fields are manipulated to change the email address of the target user to the attacker’s email.
Mitigation and Prevention
To mitigate this vulnerability, it is recommended to apply the latest patch from the vendor as soon as possible. In the meantime, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as temporary mitigation. Also, it is advisable to implement and enforce multi-factor authentication, especially for critical accounts, reducing the risk of account takeover even if the email address is changed.
