UBUNTU-CVE-2021-3653
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. This flaw affects Linux kernel versions prior to 5.14-rc7.
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
6 explicit affected versions
3 explicit affected versions
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191 explicit affected versions
69 explicit affected versions
30 explicit affected versions
49 explicit affected versions
22 explicit affected versions
80 explicit affected versions
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3 explicit affected versions
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3 explicit affected versions
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1 explicit affected versions
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1 explicit affected versions
29 explicit affected versions
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1 explicit affected versions
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10 explicit affected versions
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3 explicit affected versions
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4 explicit affected versions
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2 explicit affected versions
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1 explicit affected versions
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25 explicit affected versions
1 explicit affected versions
1 explicit affected versions
29 explicit affected versions
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1 explicit affected versions
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3 explicit affected versions
1 explicit affected versions
25 explicit affected versions
44 explicit affected versions
16 explicit affected versions
2 explicit affected versions
17 explicit affected versions
38 explicit affected versions
9 explicit affected versions
109 explicit affected versions
23 explicit affected versions
44 explicit affected versions
5 explicit affected versions
79 explicit affected versions
56 explicit affected versions
4 explicit affected versions
13 explicit affected versions
47 explicit affected versions
22 explicit affected versions
43 explicit affected versions
1 explicit affected versions
87 explicit affected versions
95 explicit affected versions
12 explicit affected versions
4 explicit affected versions
12 explicit affected versions
1 explicit affected versions
3 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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. This flaw affects Linux kernel versions prior to 5.14-rc7.
05 / REFERENCES
Further evidence
- https://github.com/torvalds/linux/commit/3d6368ef580a
- https://ubuntu.com/security/CVE-2021-3653
- https://ubuntu.com/security/notices/USN-5062-1
- https://ubuntu.com/security/notices/USN-5070-1
- https://ubuntu.com/security/notices/USN-5071-1
- https://ubuntu.com/security/notices/USN-5071-2
- https://ubuntu.com/security/notices/USN-5072-1
- https://ubuntu.com/security/notices/USN-5073-1
- https://ubuntu.com/security/notices/USN-5073-2
- https://ubuntu.com/security/notices/USN-5082-1
- https://www.cve.org/CVERecord?id=CVE-2021-3653
- https://www.openwall.com/lists/oss-security/2021/08/16/1