Risk | Low |
Patch available | YES |
Number of vulnerabilities | 2 |
CVE-ID | CVE-2021-3653 CVE-2020-36385 |
CWE-ID | CWE-264 CWE-416 |
Exploitation vector | Network |
Public exploit | N/A |
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 2 vulnerabilities.
EUVDB-ID: #VU56904
Risk: Low
CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-3653
CWE-ID:
CWE-264 - Permissions, Privileges, and Access Controls
Exploit availability: No
DescriptionThe vulnerability allows a malicious guest to escalate privileges on the system.
The vulnerability exists due to improperly imposed security restrictions within the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest.
As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
Install updates from vendor's website.
kernel (Red Hat package): 3.10.0-514.6.1.el7 - 3.10.0-514.el7
Red Hat Enterprise Linux Server - AUS: 7.3
External linkshttp://access.redhat.com/errata/RHSA-2021:4768
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
EUVDB-ID: #VU58332
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-2020-36385
CWE-ID:
CWE-416 - Use After Free
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in drivers/infiniband/core/ucma.c, because the ctx is reached via the ctx_list in some ucma_migrate_id situations where ucma_close is called. A local user can run a specially crafted program to trigger the use-after-free error and execute arbitrary code with elevated privileges.
Install updates from vendor's website.
kernel (Red Hat package): 3.10.0-514.6.1.el7 - 3.10.0-514.el7
Red Hat Enterprise Linux Server - AUS: 7.3
External linkshttp://access.redhat.com/errata/RHSA-2021:4768
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.