Xen up to 4.14.x TLB Entry memory corruption

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CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.4$5k-$25k0.00

A vulnerability, which was classified as critical, has been found in Xen up to 4.14.x (Virtualization Software). This issue affects some unknown processing of the component TLB Entry Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered in Xen through 4.14.x allowing x86 PV guest OS users to gain guest OS privileges by modifying kernel memory contents, because invalidation of TLB entries is mishandled during use of an INVLPG-like attack technique.

The weakness was published 10/23/2020. The advisory is shared at xenbits.xen.org. The identification of this vulnerability is CVE-2020-27674 since 10/22/2020. Access to the local network is required for this attack to succeed. Required for exploitation is a simple authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 11/26/2020).

Applying a patch is able to eliminate this problem.

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CPE 2.3infoedit

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CVSSv3infoedit

VulDB Meta Base Score: 6.7
VulDB Meta Temp Score: 6.4

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

NVD Base Score: 🔒

Exploitinginfoedit

Class: Memory corruption
CWE: CWE-119
ATT&CK: Unknown

Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfoedit

Threat: 🔍
Adversaries: 🔍
Geopolitics: 🔍
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Remediation: 🔍

Countermeasuresinfoedit

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfoedit

10/22/2020 CVE assigned
10/23/2020 +1 days Advisory disclosed
10/23/2020 +0 days VulDB entry created
11/26/2020 +34 days VulDB last update

Sourcesinfoedit

Advisory: xenbits.xen.org
Status: Confirmed

CVE: CVE-2020-27674 (🔒)

Entryinfoedit

Created: 10/23/2020 01:51 PM
Updated: 11/26/2020 03:29 PM
Changes: (18) vulnerability_cvss3_nvd_av vulnerability_cvss3_nvd_ac vulnerability_cvss3_nvd_pr vulnerability_cvss3_nvd_ui vulnerability_cvss3_nvd_s vulnerability_cvss3_nvd_c vulnerability_cvss3_nvd_i vulnerability_cvss3_nvd_a vulnerability_cvss2_nvd_av vulnerability_cvss2_nvd_ac vulnerability_cvss2_nvd_au vulnerability_cvss2_nvd_ci vulnerability_cvss2_nvd_ii vulnerability_cvss2_nvd_ai vulnerability_cvss3_meta_basescore vulnerability_cvss3_meta_tempscore vulnerability_cvss2_nvd_basescore vulnerability_cvss3_nvd_basescore
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