Description
ConnMan through 2.0 has a stack-based buffer overflow via a DHCPv6 Reply message. This occurs in get_domains in gdhcp/client.c. It copies a fixed NS_MAXDNAME (1025) bytes from a DHCPv6 DOMAIN_LIST (option 24) value into a 1026-byte stack buffer dns_name regardless of the actual option length, then walks DNS labels with an unbounded "c += jump + 1" loop. A crafted DHCPv6 REPLY with a DOMAIN_LIST option of >= 1025 non-zero bytes makes the label walk leave the buffer and read/write '.' past its end in attacker-chosen strides. An on-link attacker can trigger this without authentication via a forged Router Advertisement (O=1) and a forged DHCPv6 REPLY matching xid/CLIENTID with a long DOMAIN_LIST. The impact is unauthenticated on-link crash of connmand (runs as root). This was introduced in bb06c47.
References3
Metrics
- CVSS 3.1
-
7.6
HIGH
Score source: CNA
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H - EPSS — exploit probability
- 0% percentile: 23 · as of 8 November 2026
- CWE
- CWE-121
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