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Acunetix
acunetix.com › vulnerabilities › web › flask-weak-secret-key
Flask weak secret key - Vulnerabilities - Acunetix
Each Flask web application contains a secret key which used to sign session cookies for protection against cookie data tampering. It's very important that an attacker doesn't know the value of this secret key.
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Reddit
reddit.com › r/flask › do not leak your secret key, here's how an attacker might approach an exposed secret key
r/flask on Reddit: Do NOT leak your secret key, here's how an attacker might approach an exposed secret key
October 22, 2020 - Source code contains Flask secret key Secret key gives us new user input properties User input gives us an exec without builtins We bypass the exec without builtins and get a shell in a docker container We find a database in the docker container ...
Discussions

Hardcoded Flask Secrets Key - "Privilege Escalation"
In the sourcecode there are 3 relevant places that the Flask Secrets Key are hardcoded. Flask signs all their client sessions with this secret key, usually defined in an Environment Variable. In th... More on github.com
🌐 github.com
1
February 16, 2022
What are the exact uses of flask's SECRET_KEY
Another point to mention is when creating JWT tokens the Secret key can be used as the salt to hash your tokens too. It's pretty much a security key that can be used through your application More on reddit.com
🌐 r/flask
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25
June 2, 2020
Do NOT leak your secret key, here's how an attacker might approach an exposed secret key
This is nuts. Great video! More on reddit.com
🌐 r/flask
21
80
October 22, 2020
Exploiting "secure" Cookies in popular Python Web Frameworks
Why the fuck would you use the pickle module to read/maintain state? De-serialization's #1 rule has ALWAYS been don't de-serialize data from an un-known source (and in this case I'm making an addendum - a terribly guarded source). JSON works just as well and doesn't risk poisoning the namespace! And if you do use it, don't fall victim to mass assignment vulnerabilities (which is basically the same attack)! More on reddit.com
🌐 r/Python
45
95
January 27, 2013
People also ask

Why is WSGI important?

Before WSGI, Python web frameworks and servers often had specific coupling, meaning a particular web framework could only run on certain web servers. WSGI broke this limitation, enabling more flexibility and interoperability.

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snyk.io
snyk.io › blog › secure-python-flask-applications
How to secure Python Flask applications | Snyk
What is Web Server Gateway Interface (WSGI) standard?

WSGI allows for a standardized way for web servers to communicate with web applications written in Python. It's an intermediary layer that enables web servers to forward requests to a web application or framework and then deliver responses back to a client.

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snyk.io
snyk.io › blog › secure-python-flask-applications
How to secure Python Flask applications | Snyk
How does WSGI compare to similar concepts in other languages?

WSGI is similar in purpose to the Java Servlet API in Java or Rack in Ruby. These technologies abstract the details of HTTP requests and responses, allowing developers to focus on writing web application logic rather than dealing with underlying server communication.

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snyk.io
snyk.io › blog › secure-python-flask-applications
How to secure Python Flask applications | Snyk
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Medium
2h3ph3rd.medium.com › exploiting-flask-servers-with-known-secret-keys-3ddb35819028
Exploiting a Flask Server Using a Known Secret Key | by Francesco Pastore | Medium
January 13, 2025 - Exploiting a Flask Server Using a Known Secret Key How knowing the secret key of a Flask server can be used to create a custom session cookie and bypass authentication Setting a long and complex …
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Invicti
invicti.com › web-application-vulnerabilities › flask-weak-secret-key
Flask weak secret key - Web Application Vulnerabilities | Invicti
This Flask web application uses ... prevent tampering. When a weak or default secret key is used, attackers can predict or discover the key, allowing them to forge valid session cookies with arbitrary data....
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Tenable
tenable.com › plugins › was › 114434
Flask Weak Secret Key
September 24, 2024 - When a weak or easily guessable application key is used, it compromises the security of the entire application. Attackers can potentially decrypt sensitive data, forge valid session cookies, or even execute remote code in some scenarios. The secret key used to sign the cookies in the application ...
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GitHub
github.com › Paradoxis › Flask-Unsign
GitHub - Paradoxis/Flask-Unsign: Command line tool to fetch, decode, brute-force and craft session cookies of a Flask application by guessing secret keys. · GitHub
$ flask-unsign --decode --server 'https://www.example.com/login' [*] Server returned HTTP 302 (FOUND) [+] Successfully obtained session cookie: eyJsb2dnZWRfaW4iOmZhbHNlfQ.XDuWxQ.E2Pyb6x3w-NODuflHoGnZOEpbH8 {'logged_in': False} After obtaining a sample session cookie, you'll be able to attempt to brute-force the server's secret key.
Starred by 653 users
Forked by 47 users
Languages   Python
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Medium
medium.com › @sivahari0007 › flask-cookie-exploitation-2e262cac9130
Flask Cookie Exploitation. What is Flask | by siva hari | Medium
August 5, 2022 - That is why Flask by default calls them “signed cookies,” which is simply a way of storing the current session data on the client (rather than the server) in such a way that it cannot (in theory) be tampered with. ... Here is a real-time example of how to extract the secret key by using brute force.
Find elsewhere
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Snyk
snyk.io › blog › secure-python-flask-applications
How to secure Python Flask applications | Snyk
May 21, 2024 - Integrating confidential details directly into the source code poses a substantial security risk, as vicious actors can exploit this vulnerability to gain unauthorized access to various services.
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Medium
1nf1n1ty.medium.com › exploiting-ssti-in-flask-to-forge-admin-sessions-ctf-birthday-card-writeup-of-pragyan-ctf25-by-d3343ca7add2
Exploiting SSTI in Flask to Forge Admin Sessions: CTF “Birthday Card” Writeup of Pragyan CTF’25 By NIT, Trichy. | by 1nf1n1ty | Medium
February 9, 2025 - The goal is to exploit a Server-Side Template Injection (SSTI) vulnerability to leak the Flask secret key, forge a malicious admin session cookie, and retrieve the flag from the /admin/report endpoint.
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HackTricks
book.hacktricks.xyz › home › network services pentesting › pentesting web › flask
Flask - HackTricks
1 week ago - Command line tool to fetch, decode, brute-force and craft session cookies of a Flask application by guessing secret keys.
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GitHub
github.com › FreeTAKTeam › FreeTakServer › issues › 292
Hardcoded Flask Secrets Key - "Privilege Escalation" · Issue #292 · FreeTAKTeam/FreeTakServer
February 16, 2022 - In the sourcecode there are 3 relevant places that the Flask Secrets Key are hardcoded. Flask signs all their client sessions with this secret key, usually defined in an Environment Variable. In th...
Author   FreeTAKTeam
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Medium
blog.paradoxis.nl › defeating-flasks-session-management-65706ba9d3ce
Baking Flask cookies with your secrets | Paradoxis
July 31, 2021 - This means that if your secret key is easy to guess or is publicly known, an attacker can cleverly modify the session’s content without much effort (speaking of secrets being publicly known, you’d be surprised how many results are returned on GitHub if you search for secret_key). ... ‘So how would I go about actually bypassing the authentication?’, you might be asking yourself. Take the following example (which you can follow along if you copy the code earlier in this blog post): ... Having Flask installed by using pip install flask (preferably in a virtual environment so it won’t make your system messy)
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DigiNinja
digi.ninja › blog › cracked_flask.php
Cracked Flask Lab - DigiNinja
December 9, 2021 - COOKIE=`flask-unsign --sign --secret monkey --cookie "{'hello': 'world2', 'username': 'admin'}"` curl --cookie "session=$COOKIE" https://crackedflask.digi.ninja/user · Or you could just put the signing command into the curl command with backticks. Just watch the quotes if you try that: curl --cookie "session=`flask-unsign --sign --secret monkey --cookie \"{'hello': 'world2', 'username': 'admin'}\"`" https://crackedflask.digi.ninja/user
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GitHub
github.com › iltosec › chain-lab-flask-exploit
GitHub - iltosec/chain-lab-flask-exploit · GitHub
The script is designed to: Bypass ... wordlist (Rockyou.txt), the script tries to brute-force and find the secret key for the Flask session cookie, allowing unauthorized access to the web application....
Author   iltosec
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Horizon3
horizon3.ai › attack-research › disclosures › cve-2023-27524-insecure-default-configuration-in-apache-superset-leads-to-remote-code-execution
CVE-2023-27524: Insecure Default Configuration in Apache Superset Leads to Remote Code Execution | Horizon3.ai
March 9, 2026 - If the SECRET_KEY is exposed, an attacker with no prior privileges could generate and sign their own cookies and access the application, masquerading as a legitimate user. The off-the-shelf flask-unsign tool automates this work: “cracking” ...
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LinkedIn
linkedin.com › pulse › pentesting-ethical-hacking-tool-series-flask-session-cookie-vanegas
Pentesting and Ethical Hacking Tool Series: Flask Session Cookie Decoder/Encoder/BruteForce
June 1, 2023 - We use the following code to retrieve the secret key: flask-unsign --unsign --server 'http://mercury.picoctf.net:52134' --wordlist wordlist.txt
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SecureCoding
securecoding.com › home › blog › penetration testing in flask application
Penetration Testing in Flask Application - SecureCoding
December 13, 2021 - By guessing secret keys, a command-line program may fetch, decode, and craft session cookies of a Flask application.
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Vulners
vulners.com › metasploit › python flask cookie signer
Python Flask Cookie Signer - exploit database | Vulners.com
September 13, 2023 - This is a generic module which can manipulate Python Flask-based application cookies. It can retrieve, resign and decode cookies and has actions like retrieving a cookie from an HTTP(s) server, brute forcing the secret key used to sign the cookie, ...
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DEV Community
dev.to › snyk › how-to-secure-python-flask-applications-2156
How to secure Python Flask applications - DEV Community
May 22, 2024 - Integrating confidential details directly into the source code poses a substantial security risk, as vicious actors can exploit this vulnerability to gain unauthorized access to various services.