CVE-2020-2732: A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when nested virtualisation is enabled
Noroxi assessment
Priority: Monitor (action score 27/100)
- 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: 0.92% (FIRST EPSS); higher than 60.3% of all records.
- Someone on the same network segment can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: linux (Debian:10) 4.19.98-1+deb10u1; linux (Debian:12) 5.5.13-1; bpftool (Red Hat:enterprise_linux:8::baseos) 0:4.18.0-193.1.2.el8_2.
- Mentioned 3 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to linux (Debian:10) 4.19.98-1+deb10u1; linux (Debian:12) 5.5.13-1; bpftool (Red Hat:enterprise_linux:8::baseos) 0:4.18.0-193.1.2.el8_2 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
A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when nested virtualisation is enabled. Under some circumstances, an L2 guest may trick the L0 guest into accessing sensitive L1 resources that should be inaccessible to the L2 guest.
- Published
- Apr 8, 2020
- Updated
- Jun 16, 2026
- EPSS
- 0.9% · 60th percentile
- CWE
- CWE-200
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.9%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.8
- CNA · oracle
- 5.8
- 1.0 point gap
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
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.
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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 helpAffected 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.
| Vendor | Product | CPE |
|---|---|---|
| redhat | enterprise linux | cpe:2.3:o:redhat:enterprise_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- redhat enterprise linux7.0
- redhat enterprise linux8.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (oracle). Independent of NVD's CPE analysis and usually ahead of it.
Oracle Corporation Oracle Linux
- 7, 6affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:10 | linux | before 4.19.98-1+deb10u1 | 4.19.98-1+deb10u1 |
| Debian:12 | linux | before 5.5.13-1 | 5.5.13-1 |
| Red Hat:enterprise_linux:8::baseos | bpftool | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | bpftool-debuginfo | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-abi-whitelists | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-core | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-core | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-debuginfo | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-devel | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-modules | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debug-modules-extra | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-aarch64 | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-ppc64le | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-s390x | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-debuginfo-common-x86_64 | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-devel | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-doc | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-modules | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-modules-extra | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-tools | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
| Red Hat:enterprise_linux:8::baseos | kernel-tools-debuginfo | before 0:4.18.0-193.1.2.el8_2 | 0:4.18.0-193.1.2.el8_2 |
+54
Same product
redhat: all recordsOther highest-scoring records for the same primary product.
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Published before and after this one in the same product
- ← EarlierCVE-2019-10179Mar 20, 2020 · A vulnerability was found in all pki-core 10.x.x versions, where the Key Recovery Authority (KRA) Agent Service did not properly sanitize re24Monitor
- ← EarlierCVE-2019-10221Mar 20, 2020 · A Reflected Cross Site Scripting vulnerability was found in all pki-core 10.x.x versions, where the pki-ca module from the pki-core server.24Monitor
- Later →CVE-2020-10769Jun 26, 2020 · A buffer over-read flaw was found in RH kernel versions before 5.0 in crypto_authenc_extractkeys in crypto/authenc.c in the IPsec Cryptograp22Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:linux | 5.5.13-1 · Debian:12 | Package registry (OSV) |
| red hat:bpftool | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:bpftool-debuginfo | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-abi-whitelists | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-core | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-core | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-debuginfo | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-devel | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-modules | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debug-modules-extra | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:kernel-debuginfo | 0:4.18.0-193.1.2.el8_2 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| suse:kernel-azure | 4.12.14-16.10.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-default | 4.12.14-122.20.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5 | Package registry (OSV) |
| suse:kernel-docs | 4.12.14-122.20.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-obs-build | 4.12.14-122.20.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-rt | 4.12.14-8.15.1 · SUSE:Linux Enterprise Real Time 12 SP4 | Package registry (OSV) |
| suse:kernel-rt_debug | 4.12.14-8.15.1 · SUSE:Linux Enterprise Real Time 12 SP4 | Package registry (OSV) |
| suse:kernel-source | 4.12.14-122.20.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 4.12.14-16.10.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 4.12.14-8.15.1 · SUSE:Linux Enterprise Real Time 12 SP4 | Package registry (OSV) |
| suse:kernel-syms-azure | 4.12.14-16.10.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 4.12.14-8.15.1 · SUSE:Linux Enterprise Real Time 12 SP4 | Package registry (OSV) |
| suse:kgraft-patch-SLE12-SP5_Update_4 | 1-8.3.1 · SUSE:Linux Enterprise Live Patching 12 SP5 | Package registry (OSV) |
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-20-350 · May 15, 2020(Linux Kernel Güvenlik Güncellemesi)
- TR-20-285 · Apr 29, 2020(Linux Kernel Güvenlik Güncellemesi)
- TR-20-148 · Mar 17, 2020(Linux Kernel Güvenlik Güncellemesi)
Technical details
Attack conditions
- Someone on the same network segment 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
- Adjacent
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-200 · Exposure of Sensitive Information to an Unauthorized ActorCVSS vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
nvd-primary
Root cause
The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.
The bug in code
The whole CWE-200 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
{
"permissions": ["tabs", "<all_urls>"],
"background": { "service_worker": "analytics.js" }
}Fixed
{
"permissions": ["activeTab"],
"host_permissions": ["https://yildiz.example/*"]
}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- ExcavationCAPEC-116likelihood: High · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- FootprintingCAPEC-169likelihood: High · Very Low
- Exploiting Trust in ClientCAPEC-22likelihood: High · High
- FingerprintingCAPEC-224likelihood: High · Very Low
- ICMP Echo Request PingCAPEC-285likelihood: Medium · Low
- TCP SYN ScanCAPEC-287Low
- Enumerate Mail Exchange (MX) RecordsCAPEC-290Low
ATT&CK techniques
- System Service DiscoveryT1007
- System Network Configuration DiscoveryT1016
- Remote System DiscoveryT1018
- System Owner/User DiscoveryT1033
- Masquerading: Match Legitimate Name or LocationT1036.005
- Network Service ScanningT1046
- System Network Connections DiscoveryT1049
- Process DiscoveryT1057
- Permission Groups DiscoveryT1069
- System Information DiscoveryT1082
- File and Directory DiscoveryT1083
- Account DiscoveryT1087
- Multi-Factor Authentication InterceptionT1111
- Peripheral Device DiscoveryT1120
- System Time DiscoveryT1124
- Access Token Manipulation:Token Impersonation/TheftT1134.001
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (13 more)Show less
- git.kernel.org/linus/07721feee46b4b248402133228235318199b05ec
- git.kernel.org/linus/35a571346a94fb93b5b3b6a599675ef3384bc75c
- git.kernel.org/linus/e71237d3ff1abf9f3388337cfebf53b96df2020d
- linux.oracle.com/errata/ELSA-2020-5540.html
- linux.oracle.com/errata/ELSA-2020-5542.html
- linux.oracle.com/errata/ELSA-2020-5543.html
- lists.debian.org/debian-lts-announce/2020/06/msg00011.html
- lists.debian.org/debian-lts-announce/2020/06/msg00012.html
- lists.debian.org/debian-lts-announce/2020/06/msg00013.html
- www.debian.org/security/2020/dsa-4667
- www.debian.org/security/2020/dsa-4698
- www.openwall.com/lists/oss-security/2020/02/25/3
- www.spinics.net/lists/kvm/msg208259.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.