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Full vulnerability report · 2024
CVE-2021-47239High confidence

net: usb: fix possible use-after-free in smsc75xx_bind

Linux · Linux

7.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
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.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 8 Sept 2026
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2021-33887

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 actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: net: usb: fix possible use-after-free in smsc75xx_bind The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL.

What

In the Linux kernel, the following vulnerability has been resolved: net: usb: fix possible use-after-free in smsc75xx_bind The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: net: usb: fix possible use-after-free in smsc75xx_bind The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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 → Use After Free → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
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-416

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

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:L/PR:L/UI:N/S:U/C:H/I:H/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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level 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.IHighIntegrity impact: A successful attack can cause a major loss.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.
CWE-416
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2025-AVI-1057Multiples vulnérabilités dans les produits VMware

d?id=CVE-2021-47210 Référence CVE CVE-2021-47214 https://www.cve.org/CVERecord?id=CVE-2021-47214 Référence CVE CVE-2021-47215 https://www.cve.org/CVERecord?id=CVE-2021-47215 Référence CVE CVE-2021-47217 https://www.cve.org/CVERecord?id=CVE-2021-47217 Référence CVE CVE-2021-47222 https://www.cve.org/CVERecord?id=CVE-2021-47222 Référence CVE CVE-2021-47223 https://www.cve.org/CVERecord?id=CVE-2021-47223 Référence CVE CVE-2021-47226 https://www.cve.org/CVERecord?id=CVE-2021-47226 Référence CVE CVE-2021-47227 https://www.cve.org/CVERecord?id=CVE-2021-47227 Référence CVE CVE-2021-47237 https://www.cve.org/CVERecord?id=CVE-2021-47237 Référence CVE CVE-2021-47239 https://www.cve.org/CVERecord?id=CVE-2021-47239 Référence CVE CVE-2021-47250 https://www.cve.org/CVERecord?id=CVE-2021-47250 Référence CVE CVE-2021-47251 https://www.cve.org/CVERecord?id=CVE-2021-47251 Référence CVE CVE-2021-47261 https://www.cve.org/CVERecord?id=CVE-2021-47261 Référence CVE CVE-2021-47266 https://www.cve.org/CVERecord?id=CVE-2021-47266 Référence CVE CVE-2021-47316 https://www.cve.org/CVERecord?id=CVE-2021-47316 Référence CVE CVE-2021-47318 https://www.cve.org/CVERecord?id=CVE-2021-47318 Référence CVE CVE-2021-47325 https://www.cve.org/CVERecord?id=CVE-2021-47325 Référence CVE CVE-2021-47343 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0529Multiples vulnérabilités dans le noyau Linux de SUSE

ecord?id=CVE-2021-32399 Référence CVE CVE-2021-3743 https://www.cve.org/CVERecord?id=CVE-2021-3743 Référence CVE CVE-2021-4159 https://www.cve.org/CVERecord?id=CVE-2021-4159 Référence CVE CVE-2021-47100 https://www.cve.org/CVERecord?id=CVE-2021-47100 Référence CVE CVE-2021-47170 https://www.cve.org/CVERecord?id=CVE-2021-47170 Référence CVE CVE-2021-47220 https://www.cve.org/CVERecord?id=CVE-2021-47220 Référence CVE CVE-2021-47229 https://www.cve.org/CVERecord?id=CVE-2021-47229 Référence CVE CVE-2021-47231 https://www.cve.org/CVERecord?id=CVE-2021-47231 Référence CVE CVE-2021-47236 https://www.cve.org/CVERecord?id=CVE-2021-47236 Référence CVE CVE-2021-47239 https://www.cve.org/CVERecord?id=CVE-2021-47239 Référence CVE CVE-2021-47240 https://www.cve.org/CVERecord?id=CVE-2021-47240 Référence CVE CVE-2021-47246 https://www.cve.org/CVERecord?id=CVE-2021-47246 Référence CVE CVE-2021-47252 https://www.cve.org/CVERecord?id=CVE-2021-47252 Référence CVE CVE-2021-47255 https://www.cve.org/CVERecord?id=CVE-2021-47255 Référence CVE CVE-2021-47260 https://www.cve.org/CVERecord?id=CVE-2021-47260 Référence CVE CVE-2021-47288 https://www.cve.org/CVERecord?id=CVE-2021-47288 Référence CVE CVE-2021-47296 https://www.cve.org/CVERecord?id=CVE-2021-47296 Référence CVE CVE-2021-47314 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0526Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47227 Référence CVE CVE-2021-47228 https://www.cve.org/CVERecord?id=CVE-2021-47228 Référence CVE CVE-2021-47229 https://www.cve.org/CVERecord?id=CVE-2021-47229 Référence CVE CVE-2021-47230 https://www.cve.org/CVERecord?id=CVE-2021-47230 Référence CVE CVE-2021-47231 https://www.cve.org/CVERecord?id=CVE-2021-47231 Référence CVE CVE-2021-47235 https://www.cve.org/CVERecord?id=CVE-2021-47235 Référence CVE CVE-2021-47236 https://www.cve.org/CVERecord?id=CVE-2021-47236 Référence CVE CVE-2021-47237 https://www.cve.org/CVERecord?id=CVE-2021-47237 Référence CVE CVE-2021-47238 https://www.cve.org/CVERecord?id=CVE-2021-47238 Référence CVE CVE-2021-47239 https://www.cve.org/CVERecord?id=CVE-2021-47239 Référence CVE CVE-2021-47240 https://www.cve.org/CVERecord?id=CVE-2021-47240 Référence CVE CVE-2021-47241 https://www.cve.org/CVERecord?id=CVE-2021-47241 Référence CVE CVE-2021-47245 https://www.cve.org/CVERecord?id=CVE-2021-47245 Référence CVE CVE-2021-47246 https://www.cve.org/CVERecord?id=CVE-2021-47246 Référence CVE CVE-2021-47248 https://www.cve.org/CVERecord?id=CVE-2021-47248 Référence CVE CVE-2021-47249 https://www.cve.org/CVERecord?id=CVE-2021-47249 Référence CVE CVE-2021-47250 https://www.cve.org/CVERecord?id=CVE-2021-47250 Référence CVE CVE-2021-47252 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0496Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47227 Référence CVE CVE-2021-47228 https://www.cve.org/CVERecord?id=CVE-2021-47228 Référence CVE CVE-2021-47229 https://www.cve.org/CVERecord?id=CVE-2021-47229 Référence CVE CVE-2021-47230 https://www.cve.org/CVERecord?id=CVE-2021-47230 Référence CVE CVE-2021-47231 https://www.cve.org/CVERecord?id=CVE-2021-47231 Référence CVE CVE-2021-47235 https://www.cve.org/CVERecord?id=CVE-2021-47235 Référence CVE CVE-2021-47236 https://www.cve.org/CVERecord?id=CVE-2021-47236 Référence CVE CVE-2021-47237 https://www.cve.org/CVERecord?id=CVE-2021-47237 Référence CVE CVE-2021-47238 https://www.cve.org/CVERecord?id=CVE-2021-47238 Référence CVE CVE-2021-47239 https://www.cve.org/CVERecord?id=CVE-2021-47239 Référence CVE CVE-2021-47240 https://www.cve.org/CVERecord?id=CVE-2021-47240 Référence CVE CVE-2021-47241 https://www.cve.org/CVERecord?id=CVE-2021-47241 Référence CVE CVE-2021-47245 https://www.cve.org/CVERecord?id=CVE-2021-47245 Référence CVE CVE-2021-47246 https://www.cve.org/CVERecord?id=CVE-2021-47246 Référence CVE CVE-2021-47248 https://www.cve.org/CVERecord?id=CVE-2021-47248 Référence CVE CVE-2021-47249 https://www.cve.org/CVERecord?id=CVE-2021-47249 Référence CVE CVE-2021-47250 https://www.cve.org/CVERecord?id=CVE-2021-47250 Référence CVE CVE-2021-47252 https://www.cve.org/CVERecord?id=

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
200dbfcad8011e50c3cec269ed7b980836eeb1fa < 7cc8b2e05fcea6edd022d26e82091d781af8fd9b; 22c840596af0c09068b6cf948616e6496e59e07f < 64160d1741a3de5204d1a822e058e0b4cc526504; 9e6b8c1ff9d997e1fa16cbd2d60739adf6dc1bbc < c4e3be2e7742863e454ce31faf8fd0109c00050b; 9e6a3eccb28779710cbbafc4f4258d92509c6d07 < 2fc8300c9cfa5167fcb5b1a2a07db6f53e82f59b; b95fb96e6339e34694dd578fb6bde3575b01af17 < 4252bf6c2b245f47011098113d405ffad6ad5d5b; 635ac38b36255d3cfb8312cf7c471334f4d537e0 < 570a52cf3e01d19f7fd1a251dfc52b0cd86c13cb; 70c886ac93f87ae7214a0c69151a28a8075dd95b < 14616c372a7be01a2fb8c56c9d8debd232b9e43d; 46a8b29c6306d8bbfd92b614ef65a47c900d8e70 < 56b786d86694e079d8aad9b314e015cd4ac02a3d
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
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 21 May 2024 · Last source change 11 May 2026, 13:50 UTC · CWE-416 · Use After Free

CVE recordCVE.org · 5.2
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-2021-33887
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

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
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-2021-47239 · cve.blacktree.nl