Description
DHCP can add routes to a client’s routing table via the classless static route option (121). VPN-based security solutions that rely on routes to redirect traffic can be forced to leak traffic over the physical interface. An attacker on the same local network can read, disrupt, or possibly modify network traffic that was expected to be protected by the VPN.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
IETF DHCP
Default version status: affected
0affected
References
- https://datatracker.ietf.org/doc/html/rfc2131#section-7 ↗
- https://datatracker.ietf.org/doc/html/rfc3442#section-7 ↗
- https://tunnelvisionbug.com/ ↗
- https://www.leviathansecurity.com/research/tunnelvision ↗
- https://news.ycombinator.com/item?id=40279632 ↗
- https://arstechnica.com/security/2024/05/novel-attack-against-virtually-all-vpn-apps-neuters-their-entire-purpose/ ↗
- https://krebsonsecurity.com/2024/05/why-your-vpn-may-not-be-as-secure-as-it-claims/ ↗
- https://issuetracker.google.com/issues/263721377 ↗
- https://mullvad.net/en/blog/evaluating-the-impact-of-tunnelvision ↗
- https://www.zscaler.com/blogs/security-research/cve-2024-3661-k-tunnelvision-exposes-vpn-bypass-vulnerability ↗
- https://lowendtalk.com/discussion/188857/a-rogue-dhcp-server-within-your-network-can-and-will-hijack-your-vpn-traffic ↗
- https://news.ycombinator.com/item?id=40284111 ↗
- https://www.agwa.name/blog/post/hardening_openvpn_for_def_con ↗
- https://www.theregister.com/2024/05/07/vpn_tunnelvision_dhcp/ ↗
- https://support.citrix.com/article/CTX677069/cloud-software-group-security-advisory-for-cve20243661 ↗
- https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2024-00009 ↗
- https://bst.cisco.com/quickview/bug/CSCwk05814 ↗
- https://security.paloaltonetworks.com/CVE-2024-3661 ↗
- https://fortiguard.fortinet.com/psirt/FG-IR-24-170 ↗
- https://my.f5.com/manage/s/article/K000139553 ↗