Description (CNA)
Contiki-NG's DNS/mDNS resolver skip_name() in os/services/resolv/resolv.c walks DNS wire-format name labels with no packet-boundary check, and the caller in newdata() invokes it in a loop iterating nquestions times from the attacker-controlled DNS header before validating the transaction ID. An attacker who sets nquestions higher than the number of complete questions present causes skip_name() to walk past the UDP packet buffer, and the returned pointer is cast to struct dns_answer * for further memory reads. On builds with RESOLV_CONF_SUPPORTS_MDNS enabled, any peer on the local segment can trigger the read unauthenticated via a multicast UDP 5353 packet with no outstanding query required; on standard DNS builds an attacker who can inject a UDP response from port 53 during an outstanding query can trigger the same read. Impact is out-of-bounds read of uip_buf and adjacent memory, disclosing memory contents or crashing the resolver.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Contiki-NG / Contiki-NG | affected 0 before 04a3f0a0067d2ee87d1f297b6d0f4392d8c98ffe |
CWE
CWE-125
References
- https://github.com/contiki-ng/contiki-ng
- https://github.com/contiki-ng/contiki-ng/pull/3169
- https://github.com/contiki-ng/contiki-ng/commit/04a3f0a0067d2ee87d1f297b6d0f4392d8c98ffe
ADP enrichment
No English description supplied.
No references supplied.