Privilege escalation in IBM Elastic Storage System

1) Use-after-free

EUVDB-ID: #VU63838

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-4203

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error in sock_getsockopt() function in net/core/sock.c due to SO_PEERCRED and SO_PEERGROUPS race with listen() function (and connect() function) in the Linux kernel. A local user can exploit the use-after-free error and crash the system or escalate privileges on the system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

IBM Elastic Storage System: 6.1.0 - 6.1.3.1

CPE2.3

• cpe:2.3:a:ibm_corporation:ibm_elastic_storage_system:6.1.3.1:*:*:*:*:*:*:
• cpe:2.3:a:ibm_corporation:ibm_elastic_storage_system:6.1.3.0:*:*:*:*:*:*:
• cpe:2.3:a:ibm_corporation:ibm_elastic_storage_system:6.1.2.2:*:*:*:*:*:*:

External links

http://www.ibm.com/blogs/psirt/security-bulletin-linux-kernel-vulnerability-may-affect-ibm-elastic-storage-system-cve-2021-4203/
http://www.ibm.com/support/pages/node/6615961

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.

Is there known malware, which exploits this vulnerability?

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