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Full vulnerability report · 2020
CVE-2020-27825High confidence

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1)

Unknown · kernel

5.7MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Low, lowered one band.downgradedsince 4 Aug 2024

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.28% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown kernel and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

4 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.9.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.9.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.9.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.9.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2020-27825 · CSAF 2.0 · revision 41 · interimSUSE Product Security TeamCVE-2020-27825
69 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • kernel-source-azure as component of HPE Helion OpenStack 8
  • kernel-default as component of SUSE CaaS Platform 4.0
  • kernel-default-base as component of SUSE CaaS Platform 4.0
  • kernel-default-devel as component of SUSE CaaS Platform 4.0
  • kernel-devel as component of SUSE CaaS Platform 4.0
  • kernel-macros as component of SUSE CaaS Platform 4.0
  • kernel-source as component of SUSE CaaS Platform 4.0
  • reiserfs-kmp-default as component of SUSE CaaS Platform 4.0
  • kernel-default as component of SUSE Enterprise Storage 6
  • kernel-source as component of SUSE Enterprise Storage 6
  • kernel-source-azure as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • kernel-default as component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS
Summary
A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat.
Remediation
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-20325

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat.

What

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat.

Why

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How

An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.

What

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat.

Why

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

How

An attacker operating through local access may attempt exploitation with elevated privileges. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') → disrupt the affected service
Attack surface
Local
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-362 ↗

CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'). The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Denial of serviceCWE-362
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20201216Security Bulletin 16 Dec 2020

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Dec 2020, published on 16 December 2020. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-337Multiples vulnérabilités dans Google Android

d?id=CVE-2020-11284 Référence CVE CVE-2020-11285 https://www.cve.org/CVERecord?id=CVE-2020-11285 Référence CVE CVE-2020-11288 https://www.cve.org/CVERecord?id=CVE-2020-11288 Référence CVE CVE-2020-11289 https://www.cve.org/CVERecord?id=CVE-2020-11289 Référence CVE CVE-2020-11293 https://www.cve.org/CVERecord?id=CVE-2020-11293 Référence CVE CVE-2020-11294 https://www.cve.org/CVERecord?id=CVE-2020-11294 Référence CVE CVE-2020-11295 https://www.cve.org/CVERecord?id=CVE-2020-11295 Référence CVE CVE-2020-25656 https://www.cve.org/CVERecord?id=CVE-2020-25656 Référence CVE CVE-2020-27786 https://www.cve.org/CVERecord?id=CVE-2020-27786 Référence CVE CVE-2020-27825 https://www.cve.org/CVERecord?id=CVE-2020-27825 Référence CVE CVE-2020-29661 https://www.cve.org/CVERecord?id=CVE-2020-29661 Référence CVE CVE-2021-0324 https://www.cve.org/CVERecord?id=CVE-2021-0324 Référence CVE CVE-2021-0466 https://www.cve.org/CVERecord?id=CVE-2021-0466 Référence CVE CVE-2021-0467 https://www.cve.org/CVERecord?id=CVE-2021-0467 Référence CVE CVE-2021-0472 https://www.cve.org/CVERecord?id=CVE-2021-0472 Référence CVE CVE-2021-0473 https://www.cve.org/CVERecord?id=CVE-2021-0473 Référence CVE CVE-2021-0474 https://www.cve.org/CVERecord?id=CVE-2021-0474 Référence CVE CVE-2021-0475 https://www.cve.org/CVERecord?id=CVE-2021-0475

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-191Multiples vulnérabilités dans le noyau Linux de Debian LTS

De multiples vulnérabilités ont été découvertes dans le noyau Linux de Debian LTS. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à l'intégrité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-120Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2020-25211 Référence CVE CVE-2020-25285 https://www.cve.org/CVERecord?id=CVE-2020-25285 Référence CVE CVE-2020-25639 https://www.cve.org/CVERecord?id=CVE-2020-25639 Référence CVE CVE-2020-25668 https://www.cve.org/CVERecord?id=CVE-2020-25668 Référence CVE CVE-2020-25669 https://www.cve.org/CVERecord?id=CVE-2020-25669 Référence CVE CVE-2020-27068 https://www.cve.org/CVERecord?id=CVE-2020-27068 Référence CVE CVE-2020-27673 https://www.cve.org/CVERecord?id=CVE-2020-27673 Référence CVE CVE-2020-27777 https://www.cve.org/CVERecord?id=CVE-2020-27777 Référence CVE CVE-2020-27786 https://www.cve.org/CVERecord?id=CVE-2020-27786 Référence CVE CVE-2020-27825 https://www.cve.org/CVERecord?id=CVE-2020-27825 Référence CVE CVE-2020-27835 https://www.cve.org/CVERecord?id=CVE-2020-27835 Référence CVE CVE-2020-28374 https://www.cve.org/CVERecord?id=CVE-2020-28374 Référence CVE CVE-2020-28915 https://www.cve.org/CVERecord?id=CVE-2020-28915 Référence CVE CVE-2020-28974 https://www.cve.org/CVERecord?id=CVE-2020-28974 Référence CVE CVE-2020-29371 https://www.cve.org/CVERecord?id=CVE-2020-29371 Référence CVE CVE-2020-29568 https://www.cve.org/CVERecord?id=CVE-2020-29568 Référence CVE CVE-2020-29569 https://www.cve.org/CVERecord?id=CVE-2020-29569 Référence CVE CVE-2020-29660 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-077Multiples vulnérabilités dans le noyau Linux de Debian

De multiples vulnérabilités ont été découvertes dans le noyau Linux de Debian. Certaines d'entre elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une exécution de code arbitraire à distance et un déni de service à distance.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-035Multiples vulnérabilités dans le noyau Linux de SUSE

De multiples vulnérabilités ont été découvertes dans le noyau Linux de SUSE. Certaines d'entre elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une exécution de code arbitraire à distance et un contournement de la politique de sécurité.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-021Multiples vulnérabilités dans le noyau Linux de SUSE

De multiples vulnérabilités ont été découvertes dans le noyau Linux de SUSE. Certaines d'entre elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une exécution de code arbitraire à distance et un déni de service.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2020-014302Linux Kernel における競合状態に関する脆弱性

Linux Kernel には、競合状態に関する脆弱性、および解放済みメモリの使用に関する脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 11 Dec 2020 · Last source change 4 Aug 2024, 16:25 UTC · CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-20325
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2020-20325↗Vendor CSAF · SUSE Product Security Team↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-27825 · cve.blacktree.nl