Improper verification of cryptographic signature in IBM Cloud Pak for Watson AIOps

1) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU69935

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-44878

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists if an OpenID Connect provider supports the "none" algorithm, then pac4j does not refuse it without an explicit configuration on its side or for the "idtoken" response type. A remote attacker can bypass the token validation by injecting a malformed ID token using "none" as the value of "alg" key in the header with an empty signature value.

Mitigation

Install update from vendor's website.

Vulnerable software versions

IBM Cloud Pak for Watson AIOps : 3.4.2

External links

http://www.ibm.com/blogs/psirt/security-bulletin-due-to-use-of-pac4j-ibm-cloud-pak-for-watson-ai-ops-is-vulnerable-to-token-bypass-cve-2021-44878/

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.