CVE-2021-3656: fedoraproject fedora Missing Authorization

Modified

AliasesUBUNTU-CVE-2021-3656DEBIAN-CVE-2021-3656

Published 04-03-2022Last modified 03-08-2024

Vulnerability summary

CVE-2021-3656 is a high (CVSS 8.8) Missing Authorization vulnerability in fedoraproject fedora. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 51.5% of scored vulnerabilities.

Priority

Routine

Not severe (CVSS 8.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?

CVSS score

8.8/10

010

High · v3.1 (NVD)

EPSS score

0.66%

0%100%

Low · 0.00 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Timeline

04-03-2022
PublishedVulnerability first disclosed.
03-08-2024
Last modifiedVulnerability information updated.

Description

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 "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. 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.

CVSS metrics

4 scores · 3 sources · 2 versions

v3.18.8v2.07.2

EPSS trend

Probability

0.66%

Chance of exploitation in the next 30 days

Percentile

52%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.66% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu54 products

linux< 4.15.0-156.163 | < 5.4.0-84.94
linux-aws< 4.15.0-1111.118 | < 5.4.0-1056.59
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.11< 5.11.0-1017.18~20.04.1
linux-aws-5.3All versions (No fix recorded)

linux-aws-5.4< 5.4.0-1056.59~18.04.1
linux-aws-5.8All versions (No fix recorded)
linux-aws-fips< 4.15.0-2053.55 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1111.118~16.04.1
linux-azure< 4.15.0-1123.136~14.04.1 | < 4.15.0-1123.136~16.04.1 | All versions (No fix recorded) | < 5.4.0-1058.60
linux-azure-4.15< 4.15.0-1123.136
linux-azure-5.11< 5.11.0-1015.16~20.04.1
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1058.60~18.04.1
linux-azure-5.8< 5.8.0-1041.44~20.04.1
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fips< 4.15.0-2035.39 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-bluefield< 5.4.0-1019.22
linux-dell300x< 4.15.0-1027.32
linux-fips< 4.15.0-1069.78 | All versions (No fix recorded) | < 5.4.0-1033.38
linux-gcp< 4.15.0-1108.122~16.04.1 | All versions (No fix recorded) | < 5.4.0-1052.56
linux-gcp-4.15< 4.15.0-1108.122
linux-gcp-5.11< 5.11.0-1018.20~20.04.2
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1052.56~18.04.1
linux-gcp-5.8All versions (No fix recorded)
linux-gcp-edgeAll versions (No fix recorded)
linux-gcp-fips< 4.15.0-2018.20 | All versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1052.55
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.4< 5.4.0-1052.55~18.04.1
linux-gkeop< 5.4.0-1023.24
linux-gkeop-5.4< 5.4.0-1023.24~18.04.1
linux-hwe< 4.15.0-156.163~16.04.1 | All versions (No fix recorded)
linux-hwe-5.11< 5.11.0-34.36~20.04.1
linux-hwe-5.4< 5.4.0-84.94~18.04.1
linux-hwe-5.8All versions (No fix recorded)
linux-hwe-edgeAll versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvm< 4.15.0-1099.101 | < 5.4.0-1046.48
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1045.47
linux-oem-5.13< 5.13.0-1012.16
linux-oem-5.6All versions (No fix recorded)
linux-oracle< 4.15.0-1080.88~16.04.1 | < 4.15.0-1080.88 | < 5.4.0-1054.58
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.11< 5.11.0-1017.18~20.04.1
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1054.58~18.04.1
linux-oracle-5.8All versions (No fix recorded)
linux-raspi-realtimeAll versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscv-5.11< 5.11.0-1018.19~20.04.2
linux-snapdragon< 4.15.0-1112.121

Show all 54

Redhat24 products

Show all 24

Debian1 product

linux< 5.14.6-1

Fedoraproject1 product

fedoraEOL33 | 34

Linux1 product

linux_kernelEOL≥ 4.13, < 4.14.245 | ≥ 4.15, < 4.19.205 | ≥ 4.20, < 5.4.142 | ≥ 5.5, < 5.10.60 | ≥ 5.11, < 5.13.12 | 5.14 | 5.14:rc1 | 5.14:rc2 | 5.14:rc3 | 5.14:rc4 | 5.14:rc5 | 5.14:rc6

5 vendors · 81 products