m0dex/quincy · Security
TunnelVision - decloaking VPNs using DHCP
- GHSA ID
- GHSA-hqmp-g7ph-x543
- Severity
- medium
- Published
- Updated
- CVSS
- 5.3 · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CVSS v3
- 5.3 · CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Description
A new decloaking technique for nearly all VPN implementations has been found, which allows attackers to inject entries into the routing tables of unsuspecting victims using DHCP option 121. This allows attackers to redirect traffic, which is supposed to be sent encrypted over the VPN, through the physical interface handling DHCP for the network the victim's computer is connected to, effectively bypassing the VPN connection.
Impact
All users are potentially affected, as this attack vector can be used against any VPN implementation without mitigations in place.
Patches
Currently, there are no existing mitigations employed by Quincy.
Workarounds
Disabling DHCP option 121 in the DHCP client is a potential workaround, as it prevents this kind of attack.
References
CWEs
- CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor