Vulnerability identifier: #VU53540

Vulnerability risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-22160

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache Pulsar
Server applications / Conferencing, Collaboration and VoIP solutions

Vendor: Apache Foundation

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in when processing authentication requests based on JSON Web Tokens (JWT). The signature of the token is not validated if the algorithm of the presented token is set to "none". A remote attacker can bypass authentication process and connect under arbitrary account to the application, including administrative accounts.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Apache Pulsar: 2.6.0 - 2.6.3, 2.7.0, 2.5.0 - 2.5.2, 2.4.0 - 2.4.2, 2.3.0 - 2.3.2, 2.2.0 - 2.2.1, 1.17 - 1.17.5, 1.16 - 1.16.5, 1.15 - 1.15.7

---

External links
http://seclists.org/oss-sec/2021/q2/163

---

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.