Description
OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
opnsense core
Default version status: unaffected
26.1.6 to ≤ 26.7.7affected
pkg:github/opnsense/coreReferences
- https://github.com/opnsense/core/security/advisories/GHSA-864r-q4j5-5mjq ↗
- https://github.com/opnsense/core/commit/f46836d0c3d14e26d79214009bfbfa9a1eecab55 ↗
- https://github.com/opnsense/core/commit/32dc2a3e52eefef5251077f315a0f3243eedb834 ↗
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/captiveportal/cp-background-process.py#L78 ↗
- https://abraxaslabs.tech/research/opnsense-captive-lastseen-roam ↗
- https://github.com/opnsense/core ↗
- https://www.vulncheck.com/advisories/opnsense-26.1.6-through-26.7.7-captive-portal-session-takeover-via-forged-arp ↗