CVE-2021-38208

Local denial of service via NULL dereference

Published Aug 8, 2021 · Updated Aug 4, 2024

Linux kernel before 5.12.10 allows local unprivileged users to cause denial of service via a failed NFC LLCP bind followed by getsockname. In net/nfc/llcp_sock.c, a failed bind can leave service_name NULL, while llcp_sock_getname copies from that pointer without checking it, triggering a kernel NULL-pointer dereference and BUG. The attack requires local unprivileged access and NFC LLCP socket support; successful exploitation can panic or otherwise interrupt the kernel, with no stated confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Linux kernel before 5.12.10 allows local unprivileged users to cause denial of service via a failed NFC LLCP bind followed by getsockname. In net/nfc/llcp_sock.c, a failed bind can leave service_name NULL, while llcp_sock_getname copies from that pointer without checking it, triggering a kernel NULL-pointer dereference and BUG. The attack requires local unprivileged access and NFC LLCP socket support; successful exploitation can panic or otherwise interrupt the kernel, with no stated confidentiality or integrity impact.

The record

CVE
CVE-2021-38208
Published
Aug 8, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0NVDAV:L/AC:L/Au:N/C:N/I:N/A:P

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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