Limited RNG Entropy Source
Limited Random Number Generator (RNG) Entropy Source
Overview of the Vulnerability
Cryptography is used to ensure secure storage and transmission of data. When insufficient entropy is used to generate cryptographic keys, it is possible to predict or guess the keys. Insufficient entropy of a Random Number Generator (RNG) was identified which can create predictable random numbers. This can allow an attacker to guess the session ID or cryptographic key and gain access to restricted data or functionality.
Business Impact
This vulnerability can lead to reputational damage of the company through the impact to customers’ trust, and the ability of an attacker to view data. The severity of the impact to the business is dependent on the sensitivity of the accessible data being transmitted by the application.
Steps to Reproduce
Enable a HTTP interception proxy, such as Burp Suite or OWASP ZAP
Setup {{software}} to intercept and log requests
Use a browser to navigate to: {{URL}}
{{action}} to view unencrypted requests
Proof of Concept (PoC)
The screenshot below demonstrates the insufficient entropy of the RNG:
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Guidance
Provide a step-by-step walkthrough with a screenshot on how you exploited the vulnerability. This will speed triage time and result in faster rewards. Please include specific details on where you identified insufficient entropy, how you identified it, and what actions you were able to perform as a result.
Attempt to escalate the vulnerability to perform additional actions. If this is possible, provide a full Proof of Concept (PoC).
Recommendation(s)
Implement robust entropy for the cryptographic algorithms and ensure that the algorithms, protocols, and keys in place are kept up to date. It is also best practice to use multiple sources of entropy to generate random numbers so that they are not easily guessed.
For more information, refer to the following resource:
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