Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2021-47252: batman-adv: Avoid WARN_ON timing related checks

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.22% (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: Linux Linux 282baa8104af44e04c4af3e7f933b44267c7f86f, 2eb4e0b3631832a4291c8bf4c9db873f60b128c8, 45011f2973f6b52cf50db397bb27bf805f5f0e7f.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 282baa8104af44e04c4af3e7f933b44267c7f86f, 2eb4e0b3631832a4291c8bf4c9db873f60b128c8, 45011f2973f6b52cf50db397bb27bf805f5f0e7f 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

In the Linux kernel, the following vulnerability has been resolved: batman-adv: Avoid WARN_ON timing related checks The soft/batadv interface for a queued OGM can be changed during the time the OGM was queued for transmission and when the OGM is actually transmitted by the worker. But WARN_ON must be used to denote kernel bugs and not to print simple warnings. A warning can simply be printed using pr_warn.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2021-47252

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 instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • 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 (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 linux records

Running WordPress? Scan your site free with WP Lens

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
linuxlinux kernel

Affected versions

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

  • linux linux kernel3.14 and later · before 4.4.293
  • linux linux kernel4.5 and later · before 4.9.274
  • linux linux kernel4.10 and later · before 4.14.238
  • linux linux kernel4.15 and later · before 4.19.196
  • linux linux kernel4.20 and later · before 5.4.128
  • linux linux kernel5.5 and later · before 5.10.46
  • linux linux kernel5.11 and later · before 5.12.13
  • linux linux kernel5.13

Versions reported by the vendor

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

  • Linux Linux

    • 3.14affected
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 45011f2973f6b52cf50db397bb27bf805f5f0e7faffected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 6031daaaf6d5c359c99dfffa102e332df234ff09affected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 77a99aad5bc3ea105806ebae6be3cbadc2fc615eaffected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before e8e9d2968a9d08bf5c683afca182f1537edebf8daffected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before e7fbd8184fa9e85f0d648c499841cb7ff6dec9f4affected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 282baa8104af44e04c4af3e7f933b44267c7f86faffected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 2eb4e0b3631832a4291c8bf4c9db873f60b128c8affected · git
    • ef0a937f7a1450d3a133ccd83c9c7d07587e7a00 and later · before 9f460ae31c4435fd022c443a6029352217a16ac1affected · git
    • before 3.14not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.10.46-15.10.46-1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-default-basebefore 5.3.18-150200.24.194.1.150200.9.99.15.3.18-150200.24.194.1.150200.9.99.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-docsbefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-obs-buildbefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-preemptbefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-sourcebefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSkernel-symsbefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise Live Patching 15 SP2kernel-defaultbefore 5.3.18-150200.24.194.15.3.18-150200.24.194.1
SUSE:Linux Enterprise Live Patching 15 SP2kernel-livepatch-SLE15-SP2_Update_49before 1-150200.5.3.11-150200.5.3.1
SUSE:Linux Enterprise Micro 5.1kernel-rtbefore 5.3.18-150300.211.15.3.18-150300.211.1
SUSE:Linux Enterprise Micro 5.1kernel-source-rtbefore 5.3.18-150300.211.15.3.18-150300.211.1
SUSE:Linux Enterprise Server 12 SP5kernel-azurebefore 4.12.14-16.188.14.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5kernel-source-azurebefore 4.12.14-16.188.14.12.14-16.188.1
SUSE:Linux Enterprise Server 12 SP5kernel-syms-azurebefore 4.12.14-16.188.14.12.14-16.188.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47250May 21, 2024 · net: ipv4: fix memory leak in netlbl_cipsov4_add_std
    22Monitor
  • ← EarlierCVE-2021-47251May 21, 2024 · mac80211: fix skb length check in ieee80211_scan_rx()
    31Monitor
  • Later →CVE-2021-47253May 21, 2024 · drm/amd/display: Fix potential memory leak in DMUB hw_init
    22Monitor

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
Linux Linux282baa8104af44e04c4af3e7f933b44267c7f86fVendor (CNA)
Linux Linux2eb4e0b3631832a4291c8bf4c9db873f60b128c8Vendor (CNA)
Linux Linux45011f2973f6b52cf50db397bb27bf805f5f0e7fVendor (CNA)
Linux Linux6031daaaf6d5c359c99dfffa102e332df234ff09Vendor (CNA)
Linux Linux77a99aad5bc3ea105806ebae6be3cbadc2fc615eVendor (CNA)
Linux Linux9f460ae31c4435fd022c443a6029352217a16ac1Vendor (CNA)
Linux Linuxe7fbd8184fa9e85f0d648c499841cb7ff6dec9f4Vendor (CNA)
Linux Linuxe8e9d2968a9d08bf5c683afca182f1537edebf8dVendor (CNA)
debian:linux5.10.46-1 · Debian:12Package registry (OSV)
suse:kernel-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-default5.3.18-150200.24.194.1 · SUSE:Linux Enterprise Live Patching 15 SP2Package registry (OSV)
suse:kernel-default-base5.3.18-150200.24.194.1.150200.9.99.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-docs5.3.18-150200.24.194.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP2_Update_491-150200.5.3.1 · SUSE:Linux Enterprise Live Patching 15 SP2Package registry (OSV)
suse:kernel-obs-build5.3.18-150200.24.194.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-preempt5.3.18-150200.24.194.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-rt5.3.18-150300.211.1 · SUSE:Linux Enterprise Micro 5.1Package registry (OSV)
suse:kernel-source5.3.18-150200.24.194.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-source-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package registry (OSV)
suse:kernel-syms5.3.18-150200.24.194.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSSPackage registry (OSV)
suse:kernel-syms-azure4.12.14-16.188.1 · SUSE:Linux Enterprise Server 12 SP5Package 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.

No history yet (it accumulates with the daily EPSS job).

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 researchers

Finders, 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.

All national notices →

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

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

All records