9.8

CVE-2023-31129: Contiki-NG missing NULL pointer check in IPv6 neighbor discovery

Modified
Published 08-05-2023Last modified 29-01-2025

Vulnerability summary

CVE-2023-31129 is a critical (CVSS 9.8) NULL Pointer Dereference vulnerability in contiki-ng. EPSS estimates a 0.64% chance of exploitation in the next 30 days, higher than 50.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (NVD)
EPSS score
0.64%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 08-05-2023
    PublishedVulnerability first disclosed.
  2. 29-01-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.64%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.64% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Contiki-ng1 product

1 vendor · 1 product

References

2 links