CVE-2025-40710

Host Header Injection (HHI) in the Hotspot Shield VPN client

Published Jun 30, 2025 CVSS 4.0 · 2.3 Low EPSS < 1% KEV · Not listed
Description
Host Header Injection (HHI) vulnerability in the Hotspot Shield VPN client, which can induce unexpected behaviour when accessing third-party web applications through the VPN tunnel. Although such applications do not present this vulnerability per se, the use of the tunnel, together with a forged Host header, can cause the VPN client to redirect or forward HTTP requests to servers other than those originally intended, leading to consequences such as open redirects or delivery of traffic to infrastructure controlled by an attacker. This does not imply a flaw in the target applications, but in how the VPN client internally handles outgoing headers and requests.

Remediation

Vendor Solution

There is no reported solution at this time.

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-19527 Host Header Injection (HHI) vulnerability in the Hotspot Shield VPN client, which can induce unexpected behaviour when accessing third-party web applications through the VPN tunnel. Although such applications do not present this vulnerability per se, the use of the tunnel, together with a forged Host header, can cause the VPN client to redirect or forward HTTP requests to servers other than those originally intended, leading to consequences such as open redirects or delivery of traffic to infrastructure controlled by an attacker. This does not imply a flaw in the target applications, but in how the VPN client internally handles outgoing headers and requests.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Host Header Injection (HHI) vulnerability in the Hotspot Shield VPN client, which can induce unexpected behaviour when accessing third-party web applications through the VPN tunnel. Although such applications do not present this vulnerability per se, the use of the tunnel, together with a forged Host header, can cause the VPN client to redirect or forward HTTP requests to servers other than those originally intended, leading to consequences such as open redirects or delivery of traffic to infrastructure controlled by an attacker. This does not imply a flaw in the target applications, but in how the VPN client internally handles outgoing headers and requests.
Title Host Header Injection (HHI) in the Hotspot Shield VPN client
Weaknesses CWE-74
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:L/SA:N'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
INCIBE
Published
Updated
Jun 30, 2025, 11:15 AM
Reserved
Apr 16, 2025, 8:38 AM
Status
Deferred
Published
Jun 30, 2025, 11:15 AM
Modified
Jun 17, 2026, 9:22 AM