Executive Summary
Informations | |||
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Name | CVE-2021-28689 | First vendor Publication | 2021-06-11 |
Vendor | Cve | Last vendor Modification | 2023-08-08 |
Security-Database Scoring CVSS v3
Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N | |||
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Overall CVSS Score | 5.5 | ||
Base Score | 5.5 | Environmental Score | 5.5 |
impact SubScore | 3.6 | Temporal Score | 5.5 |
Exploitabality Sub Score | 1.8 | ||
Attack Vector | Local | Attack Complexity | Low |
Privileges Required | Low | User Interaction | None |
Scope | Unchanged | Confidentiality Impact | High |
Integrity Impact | None | Availability Impact | None |
Calculate full CVSS 3.0 Vectors scores |
Security-Database Scoring CVSS v2
Cvss vector : (AV:L/AC:L/Au:N/C:P/I:N/A:N) | |||
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Cvss Base Score | 2.1 | Attack Range | Local |
Cvss Impact Score | 2.9 | Attack Complexity | Low |
Cvss Expoit Score | 3.9 | Authentication | None Required |
Calculate full CVSS 2.0 Vectors scores |
Detail
x86: Speculative vulnerabilities with bare (non-shim) 32-bit PV guests 32-bit x86 PV guest kernels run in ring 1. At the time when Xen was developed, this area of the i386 architecture was rarely used, which is why Xen was able to use it to implement paravirtualisation, Xen's novel approach to virtualization. In AMD64, Xen had to use a different implementation approach, so Xen does not use ring 1 to support 64-bit guests. With the focus now being on 64-bit systems, and the availability of explicit hardware support for virtualization, fixing speculation issues in ring 1 is not a priority for processor companies. Indirect Branch Restricted Speculation (IBRS) is an architectural x86 extension put together to combat speculative execution sidechannel attacks, including Spectre v2. It was retrofitted in microcode to existing CPUs. For more details on Spectre v2, see: http://xenbits.xen.org/xsa/advisory-254.html However, IBRS does not architecturally protect ring 0 from predictions learnt in ring 1. For more details, see: https://software.intel.com/security-software-guidance/deep-dives/deep-dive-indirect-branch-restricted-speculation Similar situations may exist with other mitigations for other kinds of speculative execution attacks. The situation is quite likely to be similar for speculative execution attacks which have yet to be discovered, disclosed, or mitigated. |
Original Source
Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-28689 |
CWE : Common Weakness Enumeration
% | Id | Name |
---|---|---|
100 % | CWE-212 | Improper Cross-boundary Removal of Sensitive Data |
CPE : Common Platform Enumeration
Sources (Detail)
Source | Url |
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MISC | https://xenbits.xenproject.org/xsa/advisory-370.txt |
Alert History
Date | Informations |
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2023-08-09 17:28:40 |
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2021-09-02 01:43:55 |
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2021-06-24 21:23:13 |
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2021-06-11 21:23:07 |
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