Red Hat Enterprise Linux for Real Time 8.4 update for kernel-rt
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 3 |
| CVE-ID | CVE-2021-28950 CVE-2021-20317 CVE-2021-43267 |
| CWE-ID | CWE-834 CWE-665 CWE-119 |
| Exploitation vector | Local network |
| Public exploit | Public exploit code for vulnerability #3 is available. |
| Vulnerable software Subscribe |
Red Hat Enterprise Linux for Real Time Operating systems & Components / Operating system Red Hat Enterprise Linux for Real Time for NFV Operating systems & Components / Operating system kernel-rt (Red Hat package) Operating systems & Components / Operating system package or component |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 3 vulnerabilities.
1) Excessive Iteration
EUVDB-ID: #VU58207
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-28950
CWE-ID:
CWE-834 - Excessive Iteration
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to excessive iteration in fs/fuse/fuse_i.h in the Linux kernel. A local user can run a specially crafted program to perform a denial of service attack.
Install updates from vendor's website.
Red Hat Enterprise Linux for Real Time: 8.4
Red Hat Enterprise Linux for Real Time for NFV: 8.4
kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.10.2.rt7.83.el8_4
CPE2.3- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time_for_nfv:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.10.2.rt7.83.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.7.1.rt7.79.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
http://access.redhat.com/errata/RHSA-2021:4648
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.
2) Improper Initialization
EUVDB-ID: #VU58208
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-20317
CWE-ID:
CWE-665 - Improper Initialization
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to improper initialization the Linux kernel. A corrupted timer tree causes the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. A local user can run a specially crafted application to crash the kernel.
MitigationInstall updates from vendor's website.
Red Hat Enterprise Linux for Real Time: 8.4
Red Hat Enterprise Linux for Real Time for NFV: 8.4
kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.10.2.rt7.83.el8_4
CPE2.3- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time_for_nfv:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.10.2.rt7.83.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.7.1.rt7.79.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
http://access.redhat.com/errata/RHSA-2021:4648
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.
3) Buffer overflow
EUVDB-ID: #VU58209
Risk: Medium
CVSSv3.1: 7.9 [CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2021-43267
CWE-ID:
CWE-119 - Memory corruption
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to compromise the affected system.
The vulnerability exists due to insufficient validation of user-supplied input in net/tipc/crypto.c in the Linux kernel. The Transparent Inter-Process Communication (TIPC) functionality allows remote attackers to exploit insufficient validation of user-supplied sizes for the MSG_CRYPTO message type.
A remote attacker can send specially crafted MSG_CRYPTO messages to the affected system, trigger memory corruption and execute arbitrary code on the system.
Install updates from vendor's website.
Red Hat Enterprise Linux for Real Time: 8.4
Red Hat Enterprise Linux for Real Time for NFV: 8.4
kernel-rt (Red Hat package): 4.18.0-305.7.1.rt7.79.el8_4 - 4.18.0-305.10.2.rt7.83.el8_4
CPE2.3- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_real_time_for_nfv:8.4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.10.2.rt7.83.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:kernel-rt_redhat_package:4.18.0-305.7.1.rt7.79.el8_4:*:*:*:*:red_hat_enterprise_linux:*:
http://access.redhat.com/errata/RHSA-2021:4648
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
