Red Hat Enterprise Linux 7.4 update for kernel
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2021-32399 CVE-2021-22543 CVE-2021-22555 CVE-2021-37576 |
| CWE-ID | CWE-362 CWE-119 CWE-787 |
| Exploitation vector | Network |
| Public exploit |
Public exploit code for vulnerability #2 is available. Vulnerability #3 is being exploited in the wild. |
| Vulnerable software Subscribe |
kernel (Red Hat package) Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server - AUS Operating systems & Components / Operating system |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Race condition
EUVDB-ID: #VU55257
Risk: Low
CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-32399
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition for removal of the HCI controller within net/bluetooth/hci_request.c in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
MitigationInstall updates from vendor's website.
kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.90.2.el7
Red Hat Enterprise Linux Server - AUS: 7.4
External linkshttp://access.redhat.com/errata/RHSA-2021:3725
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: #VU56018
Risk: Low
CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2021-22543
CWE-ID:
CWE-119 - Memory corruption
Exploit availability: Yes
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error in Linux kernel when handling VM_IO|VM_PFNMAP vmas in KVM. A local user can can bypass RO checks and cause the pages to get freed while still accessible by the VMM and guest. As a result, an attacker with the ability to start and control a VM to read/write random pages of memory, can trigger memory corruption and execute arbitrary code with elevated privileges.
Install updates from vendor's website.
kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.90.2.el7
Red Hat Enterprise Linux Server - AUS: 7.4
External linkshttp://access.redhat.com/errata/RHSA-2021:3725
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. However, proof of concept for this vulnerability is available.
3) Out-of-bounds write
EUVDB-ID: #VU56017
Risk: Low
CVSSv3.1: 7.5 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C]
CVE-ID: CVE-2021-22555
CWE-ID:
CWE-787 - Out-of-bounds write
Exploit availability: Yes
Description The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.
Install updates from vendor's website.
kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.90.2.el7
Red Hat Enterprise Linux Server - AUS: 7.4
External linkshttp://access.redhat.com/errata/RHSA-2021:3725
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?
Yes. This vulnerability is being exploited in the wild.
4) Out-of-bounds write
EUVDB-ID: #VU57101
Risk: Medium
CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-37576
CWE-ID:
CWE-787 - Out-of-bounds write
Exploit availability: No
DescriptionThe vulnerability allows a remote user to escalate privileges on the system.
The vulnerability exists due to a boundary error in arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform. An attacker on KVM guest OS can cause host OS memory corruption via rtas_args.nargs and execute arbitrary code on the host OS.
Install updates from vendor's website.
kernel (Red Hat package): 3.10.0-123.1.2.el7 - 3.10.0-693.90.2.el7
Red Hat Enterprise Linux Server - AUS: 7.4
External linkshttp://access.redhat.com/errata/RHSA-2021:3725
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
