Red Hat Enterprise Linux 8 update for kernel
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2021-20317 CVE-2021-43267 |
| CWE-ID | CWE-665 CWE-119 |
| Exploitation vector | Local network |
| Public exploit | Public exploit code for vulnerability #2 is available. |
| Vulnerable software Subscribe |
Red Hat CodeReady Linux Builder for ARM 64 Operating systems & Components / Operating system Red Hat CodeReady Linux Builder for Power, little endian Operating systems & Components / Operating system Red Hat CodeReady Linux Builder for x86_64 Operating systems & Components / Operating system Red Hat Enterprise Linux for ARM 64 Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 Operating systems & Components / Operating system kernel (Red Hat package) Operating systems & Components / Operating system package or component |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) 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 CodeReady Linux Builder for ARM 64: 8.0
Red Hat CodeReady Linux Builder for Power, little endian: 8.0
Red Hat CodeReady Linux Builder for x86_64: 8.0
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
kernel (Red Hat package): before 4.18.0-348.2.1.el8_5
CPE2.3- cpe:2.3:o:red_hat:red hat codeready linux builder for arm 64:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red hat codeready linux builder for power, little endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red hat codeready linux builder for x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:
http://access.redhat.com/errata/RHSA-2021:4647
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) 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 CodeReady Linux Builder for ARM 64: 8.0
Red Hat CodeReady Linux Builder for Power, little endian: 8.0
Red Hat CodeReady Linux Builder for x86_64: 8.0
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
kernel (Red Hat package): before 4.18.0-348.2.1.el8_5
CPE2.3- cpe:2.3:o:red_hat:red hat codeready linux builder for arm 64:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red hat codeready linux builder for power, little endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red hat codeready linux builder for x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:
http://access.redhat.com/errata/RHSA-2021:4647
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.
