In today's digital landscape, SMS verification (OTP) has become a standard method of two-factor authentication (2FA) for secure user registration and login. However, web forms with OTP verification can pose a security risk if not properly protected. How can you safeguard your business against the misuse of SMS forms and protect yourself from unauthorised access and financial losses?
The hidden risks of OTP SMS forms
Any unsecured form on your website that uses SMS authentication is a potential target for hackers. The scenario is simple: an attacker identifies a vulnerability in your verification system and starts exploiting your SMS gateway account for artificially generated traffic (AGT). Instead of legitimate user verification, your system begins sending verification codes to artificially generated phone numbers, leading to unintended depletion of your credits or financial resources.
The main consequence of a compromised SMS form is unexpectedly high costs due to unauthorised message dispatches. If your system is integrated with other services, the situation can quickly spiral out of control, significantly increasing financial losses.
Real-life cases of SMS authentication Exploitation
Security incidents related to OTP form exploitation are not uncommon. According to a 2024 study by Verizon, 82% of successful cyberattacks involve human factors. Experts from platforms such as Sucuri, Wordfence and OWASP regularly report cases of compromised web forms. A single security gap in your verification process can turn your system into a tool for cybercriminals, generating unauthorised charges.
Risks associated with a compromised verification system
Instead of targeting databases or stealing user data, attackers in these cases focus on generating artificial traffic, with the primary goal of creating financial gain at the expense of the website owner. They systematically generate verification requests, leading to an uncontrolled surge in message dispatches to specific phone numbers. This not only wastes your credits, but may also cause delivery issues for genuine customers if your SMS provider detects suspicious activity and temporarily restricts your ability to send messages.
There is an effective way to counteract these risks. The foundation of security is a regular audit of your website, including system updates, secured libraries or plugins, and form monitoring. However, even with a secure website, there remains the risk of attackers taking control of your form and misusing it to generate artificial traffic. A single incident of this type can result in thousands of messages being sent, causing significant financial damage to the website owner. This is precisely where BulkGate can provide a safeguard.
Advanced protection with BulkGate API
BulkGate API represents the second line of defence for your system. It acts as an intelligent safeguard. Even if an attacker breaches your primary security measures, BulkGate’s advanced security limits prevent them from causing unlimited financial damage.
Geographic Protection for message sending
BulkGate offers an advanced geographic restriction system with three modes: no restriction, allow sending only to selected countries, or block sending to specific countries. You can configure each country individually to permit or restrict SMS delivery. If your business operates solely in Europe, for example, you can simply block message sending to high-risk countries or regions with excessive SMS fees, effectively preventing unexpected costs and potential misuse of your SMS system on foreign networks.
Setting daily API limits for SMS sending
BulkGate allows you to define daily limits for outgoing SMS messages in three key steps:
- Maximum number of API messages per day – Set a total daily cap on the number of messages that can be sent through the API. This should reflect your actual needs and act as a primary safeguard against sudden spikes in message traffic.
- Per-country message limit – Configure limits for individual countries. You can either set "No limit" or specify a custom limit for a specific country. This feature is especially useful if you send messages across multiple regions and require granular cost control.
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Action upon exceeding the limit – Choose what happens if message limits are exceeded:
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"Save messages to outbox" for later manual dispatch
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"Send tomorrow" (with the option to specify the exact time)
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"Discard messages" to prevent exceeding your budget
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These configurations ensure you stay within budget while preserving important messages that need to be sent. This gives you full control over your costs and protection against unexpected expenses caused by artificially generated traffic.
Setting limits on API requests
BulkGate allows you to set precise limits on API requests per minute and per second. If the system reaches the defined threshold, it automatically rejects further requests with an HTTP error code "429 Too Many Requests". It is essential to understand that this limit applies to API requests, not message volume, ensuring dual-layer protection—controlling both the volume of messages and the frequency of requests. This prevents attackers from overwhelming your system with rapid-fire API calls before any actual damage occurs.
Sleep soundly with BulkGate API limits
Implementing security measures for SMS authentication is not just about prevention—it is a fundamental necessity for modern businesses and financial stability.
With BulkGate API, you gain:
- Full control over your SMS verification costs
- Protection against OTP system abuse and financial losses
- Flexible limit settings tailored to your needs
- Comprehensive monitoring of your API’s security
Preventing SMS form abuse is always more effective than dealing with the consequences of a cyberattack. Do not overlook the security of your verification system—activate BulkGate API protection for free today.
If you have any questions about configuring limits in BulkGate, feel free to contact us via customer support.
Remember: A secure website + properly configured limits in BulkGate = a safer business—and, most importantly, peace of mind. And that is priceless.