Executive brief
The Login & Register Forms WordPress plugin (versions before 4.0.2) fails to properly enforce rate limits on password reset verification codes, allowing attackers to bypass attempt limits by changing their supposed source IP address. An attacker knowing a victim's email address can brute-force the 6-digit reset code and take over any account, including administrator accounts, potentially gaining full control of the website and access to all user data.
Technical details
The vulnerability is an authentication bypass in the password reset functionality that stems from keying rate-limit counters on client-controlled data (the X-Real-IP or X-Forwarded-For header) rather than server-derived values. An unauthenticated attacker can reset the 7-attempt limit by changing the header value, obtaining a fresh code and attempt counter for each iteration. The code space is only 900,000 possibilities (six digits: 100000–999999), so an attacker can brute-force it in roughly 1.7 hours across 12 concurrent reset requests using only 120 requests/second. The vulnerability affects all versions from 3.2.5 through 4.0.1; version 4.0.1 also lacks nonce validation entirely. It is only triggered when the "Reset Password Email" setting is configured to "Send Verification Code" (not the default "Send Reset Link"). A fix is available in version 4.0.2.
Affected products
- WordPress Login & Register Forms 3.2.5 to 4.0.1
Timeline
- 2026-08-05: disclosed
- 2026-08-10: advisory
- 2026-08-05: patched: Fixed in version 4.0.2