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Full vulnerability report · 2024
CVE-2021-47482High confidence

net: batman-adv: fix error handling

Linux · Linux

5.3MediumCVSS 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
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-2021-34487

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

In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.

What

In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.

Why

The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

How

An attacker operating through a network path 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: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.

Why

The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

How

An attacker operating through a network path 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
a network path → Missing Standardized Error Handling Mechanism → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account 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-544

CWE-544: Missing Standardized Error Handling Mechanism. The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.CNoneConfidentiality impact: No direct loss is represented by this metric.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
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-544
A

Official authority intelligence

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

BSI · German · WID-SEC-W-2024-1197Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service und unspezifische Angriffe

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder unspezifische Angriffe durchzuführen.

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

d?id=CVE-2021-47473 Référence CVE CVE-2021-47474 https://www.cve.org/CVERecord?id=CVE-2021-47474 Référence CVE CVE-2021-47475 https://www.cve.org/CVERecord?id=CVE-2021-47475 Référence CVE CVE-2021-47476 https://www.cve.org/CVERecord?id=CVE-2021-47476 Référence CVE CVE-2021-47477 https://www.cve.org/CVERecord?id=CVE-2021-47477 Référence CVE CVE-2021-47478 https://www.cve.org/CVERecord?id=CVE-2021-47478 Référence CVE CVE-2021-47479 https://www.cve.org/CVERecord?id=CVE-2021-47479 Référence CVE CVE-2021-47480 https://www.cve.org/CVERecord?id=CVE-2021-47480 Référence CVE CVE-2021-47481 https://www.cve.org/CVERecord?id=CVE-2021-47481 Référence CVE CVE-2021-47482 https://www.cve.org/CVERecord?id=CVE-2021-47482 Référence CVE CVE-2021-47483 https://www.cve.org/CVERecord?id=CVE-2021-47483 Référence CVE CVE-2021-47484 https://www.cve.org/CVERecord?id=CVE-2021-47484 Référence CVE CVE-2021-47485 https://www.cve.org/CVERecord?id=CVE-2021-47485 Référence CVE CVE-2021-47486 https://www.cve.org/CVERecord?id=CVE-2021-47486 Référence CVE CVE-2021-47488 https://www.cve.org/CVERecord?id=CVE-2021-47488 Référence CVE CVE-2021-47489 https://www.cve.org/CVERecord?id=CVE-2021-47489 Référence CVE CVE-2021-47490 https://www.cve.org/CVERecord?id=CVE-2021-47490 Référence CVE CVE-2021-47491 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-2021-47473 Référence CVE CVE-2021-47474 https://www.cve.org/CVERecord?id=CVE-2021-47474 Référence CVE CVE-2021-47475 https://www.cve.org/CVERecord?id=CVE-2021-47475 Référence CVE CVE-2021-47476 https://www.cve.org/CVERecord?id=CVE-2021-47476 Référence CVE CVE-2021-47477 https://www.cve.org/CVERecord?id=CVE-2021-47477 Référence CVE CVE-2021-47478 https://www.cve.org/CVERecord?id=CVE-2021-47478 Référence CVE CVE-2021-47479 https://www.cve.org/CVERecord?id=CVE-2021-47479 Référence CVE CVE-2021-47480 https://www.cve.org/CVERecord?id=CVE-2021-47480 Référence CVE CVE-2021-47481 https://www.cve.org/CVERecord?id=CVE-2021-47481 Référence CVE CVE-2021-47482 https://www.cve.org/CVERecord?id=CVE-2021-47482 Référence CVE CVE-2021-47483 https://www.cve.org/CVERecord?id=CVE-2021-47483 Référence CVE CVE-2021-47484 https://www.cve.org/CVERecord?id=CVE-2021-47484 Référence CVE CVE-2021-47485 https://www.cve.org/CVERecord?id=CVE-2021-47485 Référence CVE CVE-2021-47486 https://www.cve.org/CVERecord?id=CVE-2021-47486 Référence CVE CVE-2021-47488 https://www.cve.org/CVERecord?id=CVE-2021-47488 Référence CVE CVE-2021-47489 https://www.cve.org/CVERecord?id=CVE-2021-47489 Référence CVE CVE-2021-47490 https://www.cve.org/CVERecord?id=CVE-2021-47490 Référence CVE CVE-2021-47491 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
c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < 0c6b199f09be489c48622537a550787fc80aea73; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < 07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < e50f957652190b5a88a8ebce7e5ab14ebd0d3f00; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < fbf150b16a3635634b7dfb7f229d8fcd643c6c51; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < 6422e8471890273994fe8cc6d452b0dcd2c9483e; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < b0a2cd38553c77928ef1646ed1518486b1e70ae8; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < a8f7359259dd5923adc6129284fdad12fc5db347; c6c8fea29769d998d94fcec9b9f14d4b52b349d3 < 6f68cd634856f8ca93bafd623ba5357e0f648c68
Fixed
< 2.6.38; 4.4.293 ≤ 4.4.*; 4.9.289 ≤ 4.9.*; 4.14.254 ≤ 4.14.*; 4.19.215 ≤ 4.19.*; 5.4.157 ≤ 5.4.*; 5.10.77 ≤ 5.10.*; 5.14.16 ≤ 5.14.*
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 22 May 2024 · Last source change 11 May 2026, 13:55 UTC · CWE-544 · Missing Standardized Error Handling Mechanism

CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
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-2021-34487
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
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-2021-47482 · cve.blacktree.nl