How to prevent malicious password reset abuse and hard bounces?
Summary
What email marketers say11Marketer opinions
Email marketer from Cloudflare shares that a bot management solution helps identify and mitigate malicious bots attempting password reset attacks. These solutions analyze traffic patterns, challenge suspicious requests, and block bots, preventing them from overwhelming the system with password reset requests.
Email marketer from StackExchange explains that limiting password reset requests is a good idea. They suggest the best approach is to use a CAPTCHA after a few failed attempts to ensure a human is requesting the reset.
Email marketer from Reddit shares that implementing CAPTCHA on the password reset page, limiting the number of requests from the same IP address, and monitoring for unusual activity are effective ways to prevent abuse. They also suggest adding a delay between reset attempts.
Email marketer from Security Forums shares that implementing account lockout policies after a certain number of failed password reset attempts can deter attackers. This involves temporarily disabling the account, preventing further attempts until the user verifies their identity or contacts support. The lockout duration should be carefully chosen to balance security and usability.
Email marketer from Imperva explains that bot detection and mitigation is critical for preventing password reset abuse. Identifying and blocking bots that attempt to flood the password reset endpoint can significantly reduce the risk of account takeovers. They recommend using behavioral analysis and device fingerprinting to distinguish between legitimate users and bots.
Email marketer from troyhunt.com explains that failing to adequately protect the password reset process leaves applications vulnerable. Account enumeration, weak tokens, and lack of rate limiting are all cited as common issues that can be exploited.
Email marketer from Auth0 shares to make it extra safe, use Multi-Factor Authentication (MFA) in the password reset flow. After someone asks to reset their password but before they can actually change it, require them to prove it's really them with a second form of verification, like a code sent to their phone or email. This way, even if someone gets hold of the password reset link, they still can't change the password without that second verification step.
Marketer from Email Geeks suggests checking the user agent in logs for malicious attacks from old browser versions and to block older TLS versions.
Marketer from Email Geeks shares that if the IP address is constant, deny it at the server level or add logic to ignore the email addresses if present in the form. They suggest captcha as well.
Email marketer from security.stackexchange.com shares that increasing the complexity requirements for passwords can decrease likelihood of abuse, they say 'use passwords with a combination of upper and lower case letters, numbers and punctuation symbols'.
Email marketer from Medium.com shares that they limit the amount of email reset password request from the same IP in specific amount of time period. Example: Not more than 5 request in 10 minutes.
What the experts say5Expert opinions
Expert from Email Geeks handles bogus address submissions by limiting attempts for an address/IP, blocking probing IPs/TOR exit nodes, and using reCAPTCHA.
Expert from Spam Resource explains to use email verification with double opt-in is critical to prevent abuse and hard bounces, because it confirms that the user actually owns the email address.
Expert from Email Geeks explains that if the email addresses used in the password reset attempts are not at consumer mailbox providers (like Gmail, Hotmail, AOL, Yahoo), the bounces are unlikely to affect the sender's reputation. They suggest the attempts might be to send spam or test for security problems.
Expert from Email Geeks recommends setting a limit on the number of password reset attempts before forcing the user to contact support and looping in the security team.
Expert from Word to the Wise, explains the importance of setting up and regularly monitoring feedback loops (FBLs) with ISPs to identify and remove abusive users from your mailing lists which prevents future abuse and hard bounces.
What the documentation says3Technical articles
Documentation from Google Cloud explains that implementing rate limiting on password reset requests is crucial. Rate limiting restricts the number of password reset requests a user can make within a specific timeframe, preventing attackers from flooding the system with requests. This helps mitigate brute-force attacks and reduces the likelihood of successful account takeovers.
Documentation from Auth0 explains that to secure the password reset flow, it's crucial to use a strong, unique token for each reset request. The token should be securely stored and associated with the user's account. Also, implement checks to prevent replay attacks by invalidating the token after use and ensuring it cannot be used multiple times.
Documentation from OWASP explains that a secure password reset mechanism should involve several key elements: verifying the user's identity through a secure channel (like email), generating a strong, unpredictable reset token, and ensuring the token expires after a short period. It also recommends preventing account enumeration and implementing rate limiting to avoid abuse.