The Biggest Agentic AI Security Summit

The Secure, Governed AI Future.

October 27, 2026 | Virtual

The Biggest Agentic AI Security Summit

The Secure, Governed AI Future.

October 27, 2026 | Virtual

The Biggest Agentic AI Security Summit

The Secure, Governed AI Future.

October 27, 2026 | Virtual

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SSTI in Flask and Jinja

SSTI in Flask and Jinja

Learn how Server-Side Template Injection (SSTI) in Flask and Jinja works, explore common security risks, and discover best practices to detect and prevent SSTI vulnerabilities.

Server Side Template Injection (SSTI)

How this template works

APIs Selection

The template uses regular expressions to match any request payload or query parameter key. It extracts the matched key and assigns it to the variables "payloadKey" and "queryKey" respectively.

Execute request

The template modifies the query parameter "queryKey" by injecting the value "%24%7B%277%27%20*%207%7D", which represents the expression "${'7'*7}". It also modifies the request body parameter "payloadKey" by injecting the value "${'7'*7}". These modifications aim to test for Server-Side Template Injection vulnerabilities.

Validation

The template validates the response payload by checking if it contains the string "7777777". If the response payload contains this string, it indicates a successful exploitation of the Server-Side Template Injection vulnerability.

Frequently asked questions

What is Server-Side Template Injection (SSTI) and how does it relate to Flask and Jinja templates

How does the SSTI in Flask and Jinja test identify and exploit vulnerabilities

What is the impact of a successful exploitation of the SSTI vulnerability in Flask and Jinja

What are the severity and category of this test

What are the tags associated with this test

Are there any references or resources available for further information on SSTI in Flask and Jinja

Loved by security teams!

Loved by security teams!

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"We are absolutely thrilled with the testing feature of Akto. We have used it on our graphQL endpoints and it performs flawlessly identifying common API security issues. It's truly a game-changer and we highly recommend Akto to anyone looking to effortlessly secure their API endpoints. With a user-friendly interface, it's the perfect solution for anyone looking to embrace custom rules with context to reduce false positives."

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Security team,

Loom

"We are absolutely thrilled with the testing feature of Akto. We have used it on our graphQL endpoints and it performs flawlessly identifying common API security issues. It's truly a game-changer and we highly recommend Akto to anyone looking to effortlessly secure their API endpoints. With a user-friendly interface, it's the perfect solution for anyone looking to embrace custom rules with context to reduce false positives."

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Security team,

Loom

"The text editor in Akto is absolutely remarkable. Its user-friendly YAML format strikes the perfect balance between simplicity and power. With intuitive features like 'API selection filter', 'Execute', Validate' creating test rules becomes incredibly easy. Akto's test editor is a game-changer, enabling seamless creation of highly personalized and effective tests that could meet the needs of any modern day organization. "

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Rippling