DoLogin Security <= 4.3 - Unauthenticated Authentication Bypass via Insufficient Randomness via 'dologin' Parameter Weak PRNG Token

I cannot fulfill this request. I am prohibited from generating detailed exploitation plans, actionable payloads, or step-by-step guides for bypassing authentication mechanisms. I can, however, explain the security principles involved in this vulnerability and provide guidance on how to implement secure token generation and verification in WordPress.

Security Analysis: Weak PRNG and Authentication Bypass

The vulnerability described (CVE-2026-14495) illustrates three critical security failures common in legacy or poorly implemented authentication systems:

1. Insufficient Entropy in PRNG Seeding

The use of mt_srand((double) microtime() * 1000000) to seed a Pseudo-Random Number Generator (PRNG) is a classic security flaw.

• The Problem: In many PHP environments, microtime() returns the current Unix timestamp with microseconds. Multiplying the microsecond component by 1,000,000 and using it as a seed results in a very small state space (typically 1,000,000 possible seeds).
• The Consequence: Because the Mersenne Twister (mt_rand) is deterministic, once the seed is known or guessed, every subsequent "random" value generated (such as the characters of a magic-link token) can be predicted with 100% accuracy. An attacker can pre-calculate all 1,000,000 possible tokens and test them against the server.

2. Non-Constant-Time Comparison

Using standard equality operators like != or == for sensitive tokens introduces timing vulnerabilities.

• The Problem: These operators stop comparing as soon as they find a mismatch. The time taken for the comparison depends on how many characters at the start of the string match.
• The Consequence: An attacker can potentially measure these infinitesimal timing differences to guess a token character-by-character, although this is significantly more difficult in a web environment than a local one. In the context of a weak PRNG, this is secondary to the seed brute-forcing but still a flaw.

3. Authentication Hook Bypass

Registering login logic on the init hook without utilizing WordPress’s standard authentication framework (wp_authenticate()) can bypass security features like login rate-limiting, account lockouts, and auditing logs.

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Remediation and Secure Implementation

To securely implement "magic links" or passwordless login in WordPress, developers should follow these practices:

Cryptographically Secure Token Generation

Use PHP 7+ native functions designed for security. random_bytes() generates cryptographically strong pseudo-random bytes.

// Generate a secure 32-byte token
$token = bin2hex(random_bytes(32));

// Store the hash of the token in the database, not the token itself
$token_hash = wp_hash($token); 

Constant-Time Verification

Always use hash_equals() to compare tokens. This function takes the same amount of time regardless of whether the strings match, preventing timing attacks.

if ( hash_equals( $stored_hash, wp_hash( $user_provided_token ) ) ) {
    // Valid token
}

Proper Authentication Flow

Instead of calling wp_set_auth_cookie() directly, ensure that the process respects WordPress security best practices, including:

• Expiration: Set a short lifespan for magic links (e.g., 15–60 minutes).
• Single Use: Delete or invalidate the token immediately after a successful (or failed) use.
• Rate Limiting: Implement strict rate limiting on the endpoint to prevent brute-forcing of the link ID or the token.
• Standard Hooks: Use the authenticate filter to integrate with the WordPress login system, ensuring that other security plugins can monitor and protect the process.

For further information on secure WordPress development, I recommend reviewing the WordPress Plugin Handbook's Security section.