CVE-2023-33973Network attack vector

Device crash via unchecked encapsulated IPv6 header

Published May 30, 2023 · Updated Jan 10, 2025

NULL pointer dereference in RIOT 2023.01 and earlier allows remote attackers to crash IoT devices with a crafted forwarded 6LoWPAN frame. The _iphc_ipv6_encode function dereferences pkt->next->data without first verifying that the encapsulated IPv6 header snippet exists. The device must process and forward the malformed frame through GNRC 6LoWPAN IPHC; the demonstrated consequence is a device crash only.

CVSS severity7.5
High
EPSS probability0.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in RIOT 2023.01 and earlier allows remote attackers to crash IoT devices with a crafted forwarded 6LoWPAN frame. The _iphc_ipv6_encode function dereferences pkt->next->data without first verifying that the encapsulated IPv6 header snippet exists. The device must process and forward the malformed frame through GNRC 6LoWPAN IPHC; the demonstrated consequence is a device crash only.

The record

CVE
CVE-2023-33973
Published
May 30, 2023
Updated
Jan 10, 2025
Vendor
RIOT-OS
Product
RIOT
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2025Record 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=<= 2023.01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

RIOT-OS · RIOTversion=<= 2023.01

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
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.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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