Red Hat Enterprise Linux 6 Extended Lifecycle Support update for kernel
| Risk | Low |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2020-29661 CVE-2021-20265 CVE-2021-27364 CVE-2021-27365 |
| CWE-ID | CWE-667 CWE-400 CWE-264 CWE-119 |
| Exploitation vector | Local |
| Public exploit | N/A |
| Vulnerable software Subscribe |
kernel (Red Hat package) Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) Operating systems & Components / Operating system Red Hat Enterprise Linux Server - Extended Life Cycle Support Operating systems & Components / Operating system |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Improper locking
EUVDB-ID: #VU51543
Risk: Low
CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-29661
CWE-ID:
CWE-667 - Improper Locking
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a escalate privileges on the system.
The vulnerability exists due to locking error in the tty subsystem of the Linux kernel in drivers/tty/tty_jobctrl.c. An local user can exploit this vulnerability to trigger a use-after-free error against TIOCSPGRP and execute arbitrary code with elevated privileges.
Install updates from vendor's website.
kernel (Red Hat package): 2.6.32-71.7.1.el6 - 2.6.32-754.35.1.el6
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems): 6.0
Red Hat Enterprise Linux Server - Extended Life Cycle Support: 6.0
External linkshttp://access.redhat.com/errata/RHSA-2021:1288
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) Resource exhaustion
EUVDB-ID: #VU51548
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-2021-20265
CWE-ID:
CWE-400 - Resource exhaustion
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. A local user can trigger resource exhaustion and perform a denial of service (DoS) attack.
MitigationInstall updates from vendor's website.
kernel (Red Hat package): 2.6.32-71.7.1.el6 - 2.6.32-754.35.1.el6
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems): 6.0
Red Hat Enterprise Linux Server - Extended Life Cycle Support: 6.0
External linkshttp://access.redhat.com/errata/RHSA-2021:1288
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) Permissions, Privileges, and Access Controls
EUVDB-ID: #VU51452
Risk: Low
CVSSv3.1: 7.1 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]
CVE-ID: CVE-2021-27364
CWE-ID:
CWE-264 - Permissions, Privileges, and Access Controls
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to iscsi_if_recv_msg() allows non-root users to connect and send commands to the Linux kernel. A local user can escalate privileges on the system.
Install updates from vendor's website.
kernel (Red Hat package): 2.6.32-71.7.1.el6 - 2.6.32-754.35.1.el6
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems): 6.0
Red Hat Enterprise Linux Server - Extended Life Cycle Support: 6.0
External linkshttp://access.redhat.com/errata/RHSA-2021:1288
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: #VU51451
Risk: Low
CVSSv3.1: 7.1 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:U/RC:C]
CVE-ID: CVE-2021-27365
CWE-ID:
CWE-119 - Memory corruption
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error when processing Netlink messages in Linux kernel through 5.11.3, as certain iSCSI data structures do not have appropriate length constraints or checks, and can exceed the PAGE_SIZE value. A local unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message, trigger memory corruption and execute arbitrary code on the system with elevated privileges.
Install updates from vendor's website.
kernel (Red Hat package): 2.6.32-71.7.1.el6 - 2.6.32-754.35.1.el6
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems): 6.0
Red Hat Enterprise Linux Server - Extended Life Cycle Support: 6.0
External linkshttp://access.redhat.com/errata/RHSA-2021:1288
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.
