CVE-2021-3653
First published: Mon Jul 19 2021(Updated: )
A flaw was found in 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.
Credit: secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| redhat/kernel-rt | <0:3.10.0-1160.45.1.rt56.1185.el7 | 0:3.10.0-1160.45.1.rt56.1185.el7 |
| redhat/kernel | <0:3.10.0-1160.45.1.el7 | 0:3.10.0-1160.45.1.el7 |
| redhat/kernel | <0:3.10.0-327.101.1.el7 | 0:3.10.0-327.101.1.el7 |
| redhat/kernel | <0:3.10.0-514.95.1.el7 | 0:3.10.0-514.95.1.el7 |
| redhat/kernel | <0:3.10.0-693.95.1.el7 | 0:3.10.0-693.95.1.el7 |
| redhat/kernel | <0:3.10.0-957.84.1.el7 | 0:3.10.0-957.84.1.el7 |
| redhat/kernel | <0:3.10.0-1062.59.1.el7 | 0:3.10.0-1062.59.1.el7 |
| redhat/kernel-rt | <0:4.18.0-305.19.1.rt7.91.el8_4 | 0:4.18.0-305.19.1.rt7.91.el8_4 |
| redhat/kernel | <0:4.18.0-305.19.1.el8_4 | 0:4.18.0-305.19.1.el8_4 |
| redhat/kernel | <0:4.18.0-147.56.1.el8_1 | 0:4.18.0-147.56.1.el8_1 |
| redhat/kernel-rt | <0:4.18.0-193.68.1.rt13.118.el8_2 | 0:4.18.0-193.68.1.rt13.118.el8_2 |
| redhat/kernel | <0:4.18.0-193.68.1.el8_2 | 0:4.18.0-193.68.1.el8_2 |
| Linux Linux kernel | >=2.6.30<4.4.282 | |
| Linux Linux kernel | >=4.5<4.9.281 | |
| Linux Linux kernel | >=4.10<4.14.245 | |
| Linux Linux kernel | >=4.15<4.19.205 | |
| Linux Linux kernel | >=4.20<5.4.142 | |
| Linux Linux kernel | >=5.5<5.10.60 | |
| Linux Linux kernel | >=5.11<5.13.12 | |
| Linux Linux kernel | =5.14-rc1 | |
| Linux Linux kernel | =5.14-rc2 | |
| Linux Linux kernel | =5.14-rc3 | |
| Linux Linux kernel | =5.14-rc4 | |
| Linux Linux kernel | =5.14-rc5 | |
| Linux Linux kernel | =5.14-rc6 | |
| Redhat Enterprise Linux | =7.0 | |
| Debian Debian Linux | =9.0 | |
| redhat/kernel | <5.14 | 5.14 |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.11.10-1 6.12.5-1 |
Remedy
This vulnerability can be mitigated by disabling the nested virtualization feature: ``` # modprobe -r kvm_amd # modprobe kvm_amd nested=0 ```
Remedy
Disable nested virtualisation when loading the KVM AMD module: modprobe kvm_amd nested=0
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Reference Links
- https://www.cve.org/CVERecord?id=CVE-2021-3653 https://nvd.nist.gov/vuln/detail/CVE-2021-3653 https://www.openwall.com/lists/oss-security/2021/08/16/1
- https://bugzilla.redhat.com/show_bug.cgi?id=1983686
- https://access.redhat.com/errata/RHSA-2021:3802
- https://access.redhat.com/errata/RHSA-2021:3801
- https://access.redhat.com/errata/RHSA-2021:3767
- https://access.redhat.com/errata/RHSA-2021:4768
- https://access.redhat.com/errata/RHSA-2021:4692
- https://access.redhat.com/errata/RHSA-2021:3812
- https://access.redhat.com/errata/RHSA-2021:3987
- https://access.redhat.com/errata/RHSA-2021:3547
- https://access.redhat.com/errata/RHSA-2021:3548
- https://access.redhat.com/errata/RHSA-2021:3676
- https://access.redhat.com/errata/RHSA-2021:3909
- https://access.redhat.com/errata/RHSA-2021:3904
- https://access.redhat.com/security/cve/cve-2021-3653
- http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html
- https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
- https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html
- https://www.openwall.com/lists/oss-security/2021/08/16/1
- https://launchpad.net/bugs/cve/CVE-2021-3653
- https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=0f923e07124df069ba68d8bb12324398f4b6b709
- https://github.com/torvalds/linux/commit/3d6368ef580a
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1995451
- https://access.redhat.com/errata/RHSA-2021:81932
- https://security-tracker.debian.org/tracker/CVE-2021-3653
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3653
- https://nvd.nist.gov/vuln/detail/CVE-2021-3653
- https://ubuntu.com/security/CVE-2021-3653
Parent vulnerabilities
(Appears in the following advisories)
- collector/redhat-cve
- collector/nvd-index
- agent/type
- agent/first-publish-date
- collector/launchpad-cve
- source/Launchpad
- agent/author
- collector/redhat-bugzilla
- source/Red Hat
- alias/CVE-2021-3653
- agent/software-canonical-lookup
- agent/severity
- agent/weakness
- collector/mitre-cve
- source/MITRE
- agent/remedy
- agent/references
- collector/usn-cve
- source/Ubuntu
- agent/last-modified-date
- agent/tags
- agent/description
- collector/nvd-cve
- source/NVD
- agent/event
- collector/security-tracker-debian
- source/Debian
- agent/softwarecombine
- agent/trending
- package-manager/redhat
- vendor/linux
- canonical/linux linux kernel
- version/linux linux kernel/2.6.30
- version/linux linux kernel/4.5
- version/linux linux kernel/4.10
- version/linux linux kernel/4.15
- version/linux linux kernel/4.20
- version/linux linux kernel/5.5
- version/linux linux kernel/5.11
- version/linux linux kernel/5.14-rc1
- version/linux linux kernel/5.14-rc2
- version/linux linux kernel/5.14-rc3
- version/linux linux kernel/5.14-rc4
- version/linux linux kernel/5.14-rc5
- version/linux linux kernel/5.14-rc6
- vendor/redhat
- canonical/redhat enterprise linux
- version/redhat enterprise linux/7.0
- vendor/debian
- canonical/debian debian linux
- version/debian debian linux/9.0
- package-manager/debian