{"cve":"CVE-2023-31129","nvd":{"published":"2023-05-08T21:15:11.513","modified":"2026-06-17T05:56:19.907","status":"Modified","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.\n\nThe 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`.\n\nThe 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-476"],"references":["https://github.com/contiki-ng/contiki-ng/pull/2271","https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-x29r-5qjg-75mq","https://github.com/contiki-ng/contiki-ng/pull/2271","https://github.com/contiki-ng/contiki-ng/security/advisories/GHSA-x29r-5qjg-75mq"],"products":["contiki-ng:contiki-ng"],"source":"nvd","synced_at":"2026-10-19T21:38:18.424950729+00:00"},"epss":{"cve":"CVE-2023-31129","score":0.00644,"percentile":0.50888,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}