Privilege escalation in IBM Cloud Pak System

1) Input validation error

EUVDB-ID: #VU60007

Risk: Medium

CVSSv3.1: 8.4 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C]

CVE-ID: CVE-2021-4034

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper handling of the calling parameters count in the pkexec setuid binary, which causes the binary to execute environment variables as commands. A local user can craft environment variables in a way that they will be processed and executed by pkexec and execute arbitrary commands on the system as root.

Mitigation

Install update from vendor's website.

Vulnerable software versions

IBM Cloud Pak System: 2.3.0.1 - 2.3.3.4

External links

http://www.ibm.com/support/pages/node/6611089

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.