Red Hat Enterprise Linux 8 update for kernel-rt

1) Out-of-bounds read

EUVDB-ID: #VU57137

Risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38201

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error within the net/sunrpc/xdr.c in the Linux kernel. A remote user can perform multiple NFS 4.2 READ_PLUS operations and cause a denial of service attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Real Time - Telecommunications Update Service: 8.4

Red Hat Enterprise Linux for Real Time for NFV: 8

Red Hat Enterprise Linux for Real Time: 8

kernel-rt (Red Hat package): before 4.18.0-305.17.1.rt7.89.el8_4

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time_-_telecommunications_update_service:8.4:*:*:*:*:*:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time_for_nfv:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time:8:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:kernel-rt_redhat_package:*:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2021:3440

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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