Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in Ratpack Ratpack

Published: 2019-05-07 | Updated: 2020-07-17
Risk Low
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2019-11808
Exploitation vector Network
Public exploit N/A
Vulnerable software
Universal components / Libraries / Libraries used by multiple products

Vendor Ratpack

Security Advisory

This security advisory describes one low risk vulnerability.

1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Risk: Low

CVSSv3.1: 3.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-11808

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No


The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

Ratpack versions before 1.6.1 generate a session ID using a cryptographically weak PRNG in the JDK's ThreadLocalRandom. This means that if an attacker can determine a small window for the server start time and obtain a session ID value, they can theoretically determine the sequence of session IDs.


Install update from vendor's website.

Vulnerable software versions

Ratpack: 1.6.0

CPE External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.