CVE-2021-47347

Kernel memory corruption via oversized wireless SSID

Published May 21, 2024 · Updated Aug 5, 2026

Buffer overflow in Linux kernel wl1251_cmd_scan allows local users to corrupt kernel memory through an oversized wireless SSID. The function copies ssid_len bytes into a 32-byte ssid field without validating the length, overwriting adjacent command data and reading beyond the source buffer. Reachability requires a local scan request through nl80211 or WEXT and CAP_NET_ADMIN, sometimes delegated through wireless-management services; corruption can panic the kernel or wedge the wl1251 path.

CVSS severity8.8
High
EPSS probability0.80%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Linux kernel wl1251_cmd_scan allows local users to corrupt kernel memory through an oversized wireless SSID. The function copies ssid_len bytes into a 32-byte ssid field without validating the length, overwriting adjacent command data and reading beyond the source buffer. Reachability requires a local scan request through nl80211 or WEXT and CAP_NET_ADMIN, sometimes delegated through wireless-management services; corruption can panic the kernel or wedge the wl1251 path.

The record

CVE
CVE-2021-47347
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-120, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.31
  2. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <0f6c0488368c9ac1aa685821916fadba32f5d1ef
  3. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <115103f6e3f1c26c473766c16439c7c8b235529a
  4. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <302e2ee34c5f7c5d805b7f835d9a6f2b43474e2a
  5. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <40af3960a15339e8bbd3be50c3bc7b35e1a0b6ea
  6. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <57ad99ae3c6738ba87bad259bb57c641ca68ebf6
  7. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <c5e4a10d7bd5d4f419d8b9705dff60cf69b302a1
  8. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d10a87a3535cce2b890897914f5d0d83df669c63
  9. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d3d8b9c9c7843dce31e284927d4c9904fd5a510a
  10. Affected versionversion=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d71dddeb5380613f9ef199f3e7368fd78fb1a46e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.31; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <0f6c0488368c9ac1aa685821916fadba32f5d1ef; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <115103f6e3f1c26c473766c16439c7c8b235529a; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <302e2ee34c5f7c5d805b7f835d9a6f2b43474e2a; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <40af3960a15339e8bbd3be50c3bc7b35e1a0b6ea; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <57ad99ae3c6738ba87bad259bb57c641ca68ebf6; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <c5e4a10d7bd5d4f419d8b9705dff60cf69b302a1; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d10a87a3535cce2b890897914f5d0d83df669c63; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d3d8b9c9c7843dce31e284927d4c9904fd5a510a; version=2f01a1f58889fbfeb68b1bc1b52e4197f3333490 <d71dddeb5380613f9ef199f3e7368fd78fb1a46e

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Classic Buffer Overflow
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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