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Fencer Intel
medium 5.3

GHSA-hqmp-g7ph-x543 json

TunnelVision - decloaking VPNs using DHCP

published last yr. modified last yr.

cvss
5.3
version 3.1, GitHub
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

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 https://www.leviathansecurity.com/blog/tunnelvision

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CVSS scores

assigned by version score vector
GitHub 3.1 5.3 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
crates.io quincy
<=0.13.0
 no fix listed

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

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