Vulnerability identifier: #VU31081

Vulnerability 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

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ratpack
Universal components / Libraries / Libraries used by multiple products

Vendor: Ratpack

Description

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Ratpack: 1.6.0

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External links
http://github.com/ratpack/ratpack/commit/f2b63eb82dd71194319fd3945f5edf29b8f3a42d
http://github.com/ratpack/ratpack/issues/1448
http://github.com/ratpack/ratpack/releases/tag/v1.6.1

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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.