CVE-2019-11808 : Security Advisory and Response

Ratpack versions before 1.6.1 generate session IDs using a weak PRNG in the JDK's ThreadLocalRandom, potentially allowing attackers to deduce the sequence of session IDs.

Understanding CVE-2019-11808

Ratpack's vulnerability lies in the insecure generation of session IDs, posing a risk of session ID sequence deduction by attackers.

What is CVE-2019-11808?

Ratpack versions prior to 1.6.1 utilize a cryptographically weak PRNG in ThreadLocalRandom, enabling attackers to potentially determine the sequence of session IDs by exploiting the server start time.

The Impact of CVE-2019-11808

The vulnerability in Ratpack could lead to session ID exposure, allowing attackers to deduce the sequence of session IDs and potentially compromise user sessions.

Technical Details of CVE-2019-11808

Ratpack's vulnerability stems from the insecure session ID generation process, making it susceptible to exploitation.

Vulnerability Description

Ratpack versions earlier than 1.6.1 create session IDs using a PRNG in ThreadLocalRandom that is not secure, enabling attackers to deduce the sequence of session IDs.

Affected Systems and Versions

Affected Version: Ratpack versions before 1.6.1

Exploitation Mechanism

Attackers can exploit the vulnerability by determining a narrow time frame for server start and acquiring a session ID to deduce the sequence of session IDs.

Mitigation and Prevention

To address CVE-2019-11808, immediate steps and long-term security practices are crucial.

Immediate Steps to Take

Upgrade Ratpack to version 1.6.1 or later to mitigate the vulnerability.
Monitor for any unusual session ID patterns or sequences.

Long-Term Security Practices

Implement strong session ID generation mechanisms.
Regularly update and patch software to address security vulnerabilities.

Patching and Updates

Apply patches and updates provided by Ratpack to ensure the security of session ID generation.