CVE-2023-31129: The Contiki-NG operating system versions 4.8 and prior can be triggered to dereference a NULL pointer in the message handling code for IPv6 router sol...

Description

The Contiki-NG operating system versions 4.8 and prior can be triggered to dereference a NULL pointer in the message handling code for IPv6 router solicitiations. Contiki-NG contains an implementation of IPv6 Neighbor Discovery (ND) in the module `os/net/ipv6/uip-nd6.c`. The ND protocol includes a message type called Router Solicitation (RS), which is used to locate routers and update their address information via the SLLAO (Source Link-Layer Address Option). If the indicated source address changes, a given neighbor entry is set to the STALE state. The message handler does not check for RS messages with an SLLAO that indicates a link-layer address change that a neighbor entry can actually be created for the indicated address. The resulting pointer is used without a check, leading to the dereference of a NULL pointer of type `uip_ds6_nbr_t`. The problem has been patched in the `develop` branch of Contiki-NG, and will be included in the upcoming 4.9 release. As a workaround, users can apply Contiki-NG pull request #2271 to patch the problem directly.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.64%

46.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Contiki-Ng	Contiki-Ng	<= 4.8

References

https://github.com/contiki-ng/contiki-ng/pull/2271Product
https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-x29r-5qjg-75mqPatch, Vendor Advisory
https://github.com/contiki-ng/contiki-ng/pull/2271Product
https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-x29r-5qjg-75mqPatch, Vendor Advisory

Timeline

Published: May 8, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-31129?

The Contiki-NG operating system versions 4.8 and prior can be triggered to dereference a NULL pointer in the message handling code for IPv6 router solicitiations. Contiki-NG contains an implementation of IPv6 Neighbor Discovery (ND) in the module `os/net/ipv6/uip-nd6.c`. The ND protocol includes a message type called Router Solicitation (RS), which is used to locate routers and update their address information via the SLLAO (Source Link-Layer Address Option). If the indicated source address changes, a given neighbor entry is set to the STALE state. The message handler does not check for RS messages with an SLLAO that indicates a link-layer address change that a neighbor entry can actually be created for the indicated address. The resulting pointer is used without a check, leading to the dereference of a NULL pointer of type `uip_ds6_nbr_t`. The problem has been patched in the `develop` branch of Contiki-NG, and will be included in the upcoming 4.9 release. As a workaround, users can apply Contiki-NG pull request #2271 to patch the problem directly.

How severe is CVE-2023-31129?

CVE-2023-31129 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.64% probability of exploitation in the next 30 days.

How do I fix CVE-2023-31129?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.