CentOS 7 update for kernel
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 5 |
| CVE-ID | CVE-2020-27777 CVE-2021-22555 CVE-2021-29154 CVE-2021-29650 CVE-2021-32399 |
| CWE-ID | CWE-862 CWE-787 CWE-77 CWE-119 CWE-362 |
| Exploitation vector | Local |
| Public exploit | Vulnerability #2 is being exploited in the wild. |
| Vulnerable software |
CentOS Operating systems & Components / Operating system |
| Vendor | CentOS Project |
Security Bulletin
This security bulletin contains information about 5 vulnerabilities.
1) Missing Authorization
EUVDB-ID: #VU56242
Risk: Low
CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2020-27777
CWE-ID:
CWE-862 - Missing Authorization
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to the way RTAS handles memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like user could use this flaw to further increase their privileges to that of a running kernel.
MitigationUpdate the affected packages.
Vulnerable software versionsCentOS: 7
CPE2.3 External linkshttps://lists.centos.org/pipermail/centos-announce/2021-August/048356.html
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) Out-of-bounds write
EUVDB-ID: #VU56017
Risk: Low
CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear]
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.
Update the affected packages.
Vulnerable software versionsCentOS: 7
CPE2.3 External linkshttps://lists.centos.org/pipermail/centos-announce/2021-August/048356.html
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) Command Injection
EUVDB-ID: #VU56241
Risk: Low
CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2021-29154
CWE-ID:
CWE-77 - Command injection
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to incorrect computation of branch displacements within the BPF JIT compilers in the Linux kernel in arch/x86/net/bpf_jit_comp.c and arch/x86/net/bpf_jit_comp32.c. A local user can inject and execute arbitrary commands with elevated privileges.
Update the affected packages.
Vulnerable software versionsCentOS: 7
CPE2.3 External linkshttps://lists.centos.org/pipermail/centos-announce/2021-August/048356.html
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.
4) Buffer overflow
EUVDB-ID: #VU56240
Risk: Low
CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2021-29650
CWE-ID:
CWE-119 - Memory corruption
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error within the netfilter subsystem in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h. A local user can trigger memory corruption upon the assignment of a new table value and cause denial of service.
Update the affected packages.
Vulnerable software versionsCentOS: 7
CPE2.3 External linkshttps://lists.centos.org/pipermail/centos-announce/2021-August/048356.html
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.
5) Race condition
EUVDB-ID: #VU55257
Risk: Low
CVSSv4.0: 4.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
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.
MitigationUpdate the affected packages.
Vulnerable software versionsCentOS: 7
CPE2.3 External linkshttps://lists.centos.org/pipermail/centos-announce/2021-August/048356.html
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.
