Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 5 |
CVE-ID | CVE-2021-22543 CVE-2021-3653 CVE-2021-3656 CVE-2021-22555 CVE-2021-37576 |
CWE-ID | CWE-119 CWE-264 CWE-787 |
Exploitation vector | Network |
Public exploit |
Public exploit code for vulnerability #1 is available. Vulnerability #4 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 for x86_64 - Update Services for SAP Solutions Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions Operating systems & Components / Operating system package or component Red Hat Enterprise Linux Server - TUS Operating systems & Components / Operating system Red Hat Enterprise Linux Server - AUS Operating systems & Components / Operating system |
Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 5 vulnerabilities.
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): 3.10.0-957.1.3.el7 - 3.10.0-957.el7
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server - TUS: 7.6
Red Hat Enterprise Linux Server - AUS: 7.6
External linkshttp://access.redhat.com/errata/RHSA-2021:3812
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.
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): 3.10.0-957.1.3.el7 - 3.10.0-957.el7
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server - TUS: 7.6
Red Hat Enterprise Linux Server - AUS: 7.6
External linkshttp://access.redhat.com/errata/RHSA-2021:3812
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: #VU56929
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-2021-3656
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 "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest.The vulnerability allows the L2 guest 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): 3.10.0-957.1.3.el7 - 3.10.0-957.el7
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server - TUS: 7.6
Red Hat Enterprise Linux Server - AUS: 7.6
External linkshttp://access.redhat.com/errata/RHSA-2021:3812
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.
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): 3.10.0-957.1.3.el7 - 3.10.0-957.el7
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server - TUS: 7.6
Red Hat Enterprise Linux Server - AUS: 7.6
External linkshttp://access.redhat.com/errata/RHSA-2021:3812
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.
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): 3.10.0-957.1.3.el7 - 3.10.0-957.el7
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions: 7.6
Red Hat Enterprise Linux Server - TUS: 7.6
Red Hat Enterprise Linux Server - AUS: 7.6
External linkshttp://access.redhat.com/errata/RHSA-2021:3812
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.