Description

LangBot before 4.10.11 generates password recovery keys with only 24 bits of entropy and applies no rate limiting to the unauthenticated reset-password endpoint. Remote attackers knowing the administrator email can exhaust the keyspace through concurrent requests to reset the admin password and gain account access.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.1",
  "pubDate": "2026-09-13T11:17:00.780Z",
  "pubdate": "2026-09-13T11:17:00.780Z",
  "executiveSummary": "LangBot versions prior to 4.10.11 contain a critical security vulnerability involving the password recovery mechanism. The system generates password reset tokens with insufficient entropy, providing only 24 bits of randomness. Compounding this, the application fails to implement rate limiting on the unauthenticated password reset endpoint. This combination allows remote, unauthenticated attackers to conduct brute-force attacks against the keyspace of specific user accounts, including administrative accounts, if the target email address is known. Successful exploitation enables unauthorized account takeover by resetting the victim's credentials. The risk is considered high due to the ease of automation and the potential for full administrative compromise without requiring prior authentication.",
  "technicalDetails": "The vulnerability resides within the password recovery workflow of LangBot, specifically affecting the token generation logic and the HTTP request handling for the reset password endpoint. The core security flaw is twofold: weak cryptographic strength and the absence of traffic throttling.\nRoot Cause Analysis: The token generation function utilizes a PRNG or entropy source that results in a keyspace restricted to 2^24 (16,777,216) possible combinations. This keyspace is computationally trivial to exhaust, particularly when compared to modern cryptographic standards which require at least 128 bits of entropy to remain resistant to brute-force attacks. Furthermore, the password reset endpoint lacks any rate-limiting, account-locking, or CAPTCHA mechanisms to prevent rapid-fire requests.\nExploitation Flow: An attacker initiates the exploit by supplying a known administrator email address to the unauthenticated password recovery endpoint. Once the server generates a reset token, the attacker uses an automated script to perform concurrent, high-volume requests to guess the valid token. Given the 24-bit constraint, the entire keyspace can be exhausted in a relatively short timeframe, especially if the attacker leverages multiple concurrent network connections to circumvent potential latency.\nTechnical Impact: By successfully guessing the correct 24-bit token, the attacker is granted the ability to define a new password for the administrator account. This bypasses the requirement for legitimate password reset verification, leading to full unauthorized access. Because there is no authentication requirement and the endpoint is network-exposed, the attack vector is categorized as remote and unauthenticated. The post-exploitation impact includes complete administrative control over the LangBot instance, potential data exfiltration, system configuration changes, and the ability to execute further attacks within the environment under the guise of an administrator.\nAffected Versions: All LangBot versions prior to 4.10.11 are confirmed as vulnerable. The lack of backend controls on the reset endpoint ensures that the susceptibility persists regardless of the network environment, provided the service is reachable."
}