Cisa-cgVULNRICHMENT:CVE-2024-3661CVE-2024-3661 DHCP routing options can manipulate interface-based VPN traffic
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
AI Score
Confidence
Low
SSVC
Exploitation
none
Automatable
no
Technical Impact
partial
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.
References
arstechnica.com/security/2024/05/novel-attack-against-virtually-all-vpn-apps-neuters-their-entire-purpose/
bst.cisco.com/quickview/bug/CSCwk05814
datatracker.ietf.org/doc/html/rfc2131#section-7
datatracker.ietf.org/doc/html/rfc3442#section-7
fortiguard.fortinet.com/psirt/FG-IR-24-170
issuetracker.google.com/issues/263721377
krebsonsecurity.com/2024/05/why-your-vpn-may-not-be-as-secure-as-it-claims/
lowendtalk.com/discussion/188857/a-rogue-dhcp-server-within-your-network-can-and-will-hijack-your-vpn-traffic
mullvad.net/en/blog/evaluating-the-impact-of-tunnelvision
my.f5.com/manage/s/article/K000139553
news.ycombinator.com/item?id=40279632
news.ycombinator.com/item?id=40284111
security.paloaltonetworks.com/CVE-2024-3661
support.citrix.com/article/CTX677069/cloud-software-group-security-advisory-for-cve20243661
tunnelvisionbug.com/
www.agwa.name/blog/post/hardening_openvpn_for_def_con
www.leviathansecurity.com/research/tunnelvision
www.theregister.com/2024/05/07/vpn_tunnelvision_dhcp/
www.watchguard.com/wgrd-psirt/advisory/wgsa-2024-00009
www.zscaler.com/blogs/security-research/cve-2024-3661-k-tunnelvision-exposes-vpn-bypass-vulnerability
Related
CVSS3
Attack Vector
ADJACENT
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
AI Score
Confidence
Low
SSVC
Exploitation
none
Automatable
no
Technical Impact
partial