Skip to content
Noroxi
NVD / CVE Program· CNA redhat

CVE-2021-20295: It was discovered that the update for the virt:rhel module in the RHSA-2020:4676 (https://access.redhat.com/errata/RHSA-2020:4676) erratum…

MediumCVSS 6.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.29% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: hivex (AlmaLinux:8) 1.3.18-20.module_el8.3.0+2048+e7a0a3ea; hivex-devel (AlmaLinux:8) 1.3.18-20.module_el8.3.0+2048+e7a0a3ea; libguestfs-winsupport (AlmaLinux:8) 8.2-1.module_el8.5.0+2608+72063365, 8.2-1.module_el8.3.0+2048+e7a0a3ea.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to hivex (AlmaLinux:8) 1.3.18-20.module_el8.3.0+2048+e7a0a3ea; hivex-devel (AlmaLinux:8) 1.3.18-20.module_el8.3.0+2048+e7a0a3ea; libguestfs-winsupport (AlmaLinux:8) 8.2-1.module_el8.5.0+2608+72063365, 8.2-1.module_el8.3.0+2048+e7a0a3ea or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

It was discovered that the update for the virt:rhel module in the RHSA-2020:4676 (https://access.redhat.com/errata/RHSA-2020:4676) erratum released as part of Red Hat Enterprise Linux 8.3 failed to include the fix for the qemu-kvm component issue CVE-2020-10756, which was previously corrected in virt:rhel/qemu-kvm via erratum RHSA-2020:4059 (https://access.redhat.com/errata/RHSA-2020:4059). CVE-2021-20295 was assigned to that Red Hat specific security regression. For more details about the original security issue CVE-2020-10756, refer to bug 1835986 or the CVE page: https://access.redhat.com/security/cve/CVE-2020-10756.

Published
Apr 1, 2022
Updated
Jun 16, 2026
EPSS
0.2% · 22th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-20295

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for qemu records
Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
qemuqemu

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a QEMU

    • qemu-kvm 4.2.0-34affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • qemu qemubefore 4.2.0-34

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8hivexbefore 1.3.18-20.module_el8.3.0+2048+e7a0a3ea1.3.18-20.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8hivex-develbefore 1.3.18-20.module_el8.3.0+2048+e7a0a3ea1.3.18-20.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libguestfs-winsupportbefore 8.2-1.module_el8.5.0+2608+720633658.2-1.module_el8.5.0+2608+72063365
AlmaLinux:8libguestfs-winsupportbefore 8.2-1.module_el8.3.0+2048+e7a0a3ea8.2-1.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libiscsibefore 1.18.0-8.module_el8.5.0+2608+720633651.18.0-8.module_el8.5.0+2608+72063365
AlmaLinux:8libiscsibefore 1.18.0-8.module_el8.6.0+2880+7d9e37031.18.0-8.module_el8.6.0+2880+7d9e3703
AlmaLinux:8libiscsibefore 1.18.0-8.module_el8.3.0+2048+e7a0a3ea1.18.0-8.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libiscsi-develbefore 1.18.0-8.module_el8.6.0+2880+7d9e37031.18.0-8.module_el8.6.0+2880+7d9e3703
AlmaLinux:8libiscsi-develbefore 1.18.0-8.module_el8.3.0+2048+e7a0a3ea1.18.0-8.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libiscsi-develbefore 1.18.0-8.module_el8.5.0+2608+720633651.18.0-8.module_el8.5.0+2608+72063365
AlmaLinux:8libiscsi-utilsbefore 1.18.0-8.module_el8.6.0+2880+7d9e37031.18.0-8.module_el8.6.0+2880+7d9e3703
AlmaLinux:8libiscsi-utilsbefore 1.18.0-8.module_el8.3.0+2048+e7a0a3ea1.18.0-8.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libiscsi-utilsbefore 1.18.0-8.module_el8.5.0+2608+720633651.18.0-8.module_el8.5.0+2608+72063365
AlmaLinux:8libnbdbefore 1.2.2-1.module_el8.5.0+2608+720633651.2.2-1.module_el8.5.0+2608+72063365
AlmaLinux:8libnbdbefore 1.2.2-1.module_el8.3.0+2048+e7a0a3ea1.2.2-1.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libnbd-develbefore 1.2.2-1.module_el8.3.0+2048+e7a0a3ea1.2.2-1.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libnbd-develbefore 1.2.2-1.module_el8.5.0+2608+720633651.2.2-1.module_el8.5.0+2608+72063365
AlmaLinux:8libvirt-dbusbefore 1.3.0-2.module_el8.3.0+2048+e7a0a3ea1.3.0-2.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8libvirt-dbusbefore 1.3.0-2.module_el8.6.0+2880+7d9e37031.3.0-2.module_el8.6.0+2880+7d9e3703
AlmaLinux:8libvirt-dbusbefore 1.3.0-2.module_el8.5.0+2608+720633651.3.0-2.module_el8.5.0+2608+72063365
AlmaLinux:8nbdfusebefore 1.2.2-1.module_el8.5.0+2608+720633651.2.2-1.module_el8.5.0+2608+72063365
AlmaLinux:8nbdfusebefore 1.2.2-1.module_el8.3.0+2048+e7a0a3ea1.2.2-1.module_el8.3.0+2048+e7a0a3ea
AlmaLinux:8nbdkitbefore 1.16.2-4.module_el8.5.0+2608+720633651.16.2-4.module_el8.5.0+2608+72063365
AlmaLinux:8nbdkit-bash-completionbefore 1.16.2-4.module_el8.5.0+2608+720633651.16.2-4.module_el8.5.0+2608+72063365

+96

Same product

qemu: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-12928The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote attacker to…
    60This week
  • CVE-2015-8556Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
    44Plan
  • CVE-2017-15118A stack-based buffer overflow vulnerability was found in NBD server implementation in qemu before 2.11 allowing a client to request an…
    43Plan

Published before and after this one in the same product

  • ← EarlierCVE-2021-3582Mar 25, 2022 · A flaw was found in the QEMU implementation of VMWare's paravirtual RDMA device.
    26Monitor
  • ← EarlierCVE-2022-1050Mar 29, 2022 · A flaw was found in the QEMU implementation of VMWare's paravirtual RDMA device.
    35Monitor
  • Later →CVE-2021-4206Apr 29, 2022 · A flaw was found in the QXL display device emulation in QEMU.
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:hivex1.3.18-20.module_el8.3.0+2048+e7a0a3ea · AlmaLinux:8Package registry (OSV)
almalinux:hivex-devel1.3.18-20.module_el8.3.0+2048+e7a0a3ea · AlmaLinux:8Package registry (OSV)
almalinux:libguestfs-winsupport8.2-1.module_el8.5.0+2608+72063365 · AlmaLinux:8Package registry (OSV)
almalinux:libiscsi1.18.0-8.module_el8.6.0+2880+7d9e3703 · AlmaLinux:8Package registry (OSV)
almalinux:libiscsi-devel1.18.0-8.module_el8.6.0+2880+7d9e3703 · AlmaLinux:8Package registry (OSV)
almalinux:libiscsi-utils1.18.0-8.module_el8.3.0+2048+e7a0a3ea · AlmaLinux:8Package registry (OSV)
almalinux:libnbd1.2.2-1.module_el8.5.0+2608+72063365 · AlmaLinux:8Package registry (OSV)
almalinux:libnbd-devel1.2.2-1.module_el8.3.0+2048+e7a0a3ea · AlmaLinux:8Package registry (OSV)
almalinux:libvirt-dbus1.3.0-2.module_el8.6.0+2880+7d9e3703 · AlmaLinux:8Package registry (OSV)
almalinux:nbdfuse1.2.2-1.module_el8.3.0+2048+e7a0a3ea · AlmaLinux:8Package registry (OSV)
almalinux:nbdkit1.16.2-4.module_el8.5.0+2608+72063365 · AlmaLinux:8Package registry (OSV)
almalinux:nbdkit-bash-completion1.16.2-4.module_el8.5.0+2608+72063365 · AlmaLinux:8Package registry (OSV)
red hat:hivex0:1.3.18-20.module+el8.3.0+6423+e4cb6418 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:hivex-debuginfo0:1.3.18-20.module+el8.3.0+6423+e4cb6418 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:hivex-debugsource0:1.3.18-20.module+el8.3.0+6423+e4cb6418 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:hivex-devel0:1.3.18-20.module+el8.3.0+6423+e4cb6418 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-bash-completion1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-benchmarking1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-benchmarking-debuginfo1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-debuginfo1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-debugsource1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:libguestfs-devel1:1.40.2-25.module+el8.3.0+7421+642fe24f · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:SLOF0:20191022-3.git899d9883.module+el8.3.0+6423+e4cb6418 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
rocky linux:hivex0:1.3.18-20.module+el8.4.0+534+4680a14e · Rocky Linux:8Package registry (OSV)
rocky linux:libguestfs-winsupport0:8.2-1.module+el8.4.0+534+4680a14e · Rocky Linux:8Package registry (OSV)
rocky linux:libiscsi0:1.18.0-8.module+el8.7.0+1084+97b81f61 · Rocky Linux:8Package registry (OSV)
rocky linux:libnbd0:1.2.2-1.module+el8.4.0+534+4680a14e · Rocky Linux:8Package registry (OSV)
rocky linux:libvirt-dbus0:1.3.0-2.module+el8.7.0+1084+97b81f61 · Rocky Linux:8Package registry (OSV)
rocky linux:libvirt-python0:6.0.0-1.module+el8.4.0+534+4680a14e · Rocky Linux:8Package registry (OSV)

+6

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records