DHCP routing options can manipulate interface-based VPN traffic
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · Low · Low
- Fix status
- Partial Red Hat: 9 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-306.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| IETF | DHCP | all versions | — | No fix listed | CNA |
- DHCP VendorIETF Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 26
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:linux:*:* | 6.4.0 to before 7.2.5 | Vulnerable | Fortinet |
| cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:macos:*:* | 6.4.0 to before 7.2.5 | Vulnerable | Fortinet |
| cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:windows:*:* | 6.4.0 to before 7.2.5 | Vulnerable | Fortinet |
| cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:linux:*:* | 7.4.0 | Vulnerable | Fortinet |
| cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:macos:*:* | 7.4.0 | Vulnerable | Fortinet |
| cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:windows:*:* | 7.4.0 | Vulnerable | Fortinet |
| cpe:2.3:a:cisco:anyconnect_vpn_client:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Cisco |
| cpe:2.3:a:cisco:secure_client:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Cisco |
| cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:iphone_os:*:* | all versions | Vulnerable | CyberArk Software, a Palo Alto Networks Company |
| cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:linux:*:* | all versions | Vulnerable | CyberArk Software, a Palo Alto Networks Company |
- cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:linux:*:* Versions 6.4.0 to before 7.2.5 Vulnerable ·Fortinet
- cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:macos:*:* Versions 6.4.0 to before 7.2.5 Vulnerable ·Fortinet
- cpe:2.3:a:fortinet:forticlient:*:*:*:*:*:windows:*:* Versions 6.4.0 to before 7.2.5 Vulnerable ·Fortinet
- cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:linux:*:* Versions 7.4.0 Vulnerable ·Fortinet
- cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:macos:*:* Versions 7.4.0 Vulnerable ·Fortinet
- cpe:2.3:a:fortinet:forticlient:7.4.0:*:*:*:*:windows:*:* Versions 7.4.0 Vulnerable ·Fortinet
- cpe:2.3:a:cisco:anyconnect_vpn_client:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Cisco
- cpe:2.3:a:cisco:secure_client:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Cisco
- cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:iphone_os:*:* Versions all versions Vulnerable ·CyberArk Software, a Palo Alto Networks Company
- cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:linux:*:* Versions all versions Vulnerable ·CyberArk Software, a Palo Alto Networks Company
Show 16 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:macos:*:* | all versions | Vulnerable | CyberArk Software, a Palo Alto Networks Company |
| cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:windows:*:* | all versions | Vulnerable | CyberArk Software, a Palo Alto Networks Company |
| cpe:2.3:a:citrix:secure_access_client:*:*:*:*:*:*:*:* | before 24.06.1 | Vulnerable | Citrix |
| cpe:2.3:o:apple:iphone_os:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Apple |
| cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Apple |
| cpe:2.3:a:citrix:secure_access_client:*:*:*:*:*:*:*:* | before 24.8.5 | Vulnerable | Citrix |
| cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Linux |
| cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* | 7.2.3 – 7.2.5; 15.1.0 – 15.1.10; 16.1.0 – 16.1.5; 17.1.0 – 17.1.2 | Vulnerable | F5 |
| cpe:2.3:a:watchguard:ipsec_mobile_vpn_client:*:*:*:*:*:macos:*:* | all versions | Vulnerable | WatchGuard |
| cpe:2.3:a:watchguard:ipsec_mobile_vpn_client:*:*:*:*:*:windows:*:* | all versions | Vulnerable | WatchGuard |
| cpe:2.3:a:watchguard:mobile_vpn_with_ssl:*:*:*:*:*:macos:*:* | all versions | Vulnerable | WatchGuard |
| cpe:2.3:a:watchguard:mobile_vpn_with_ssl:*:*:*:*:*:windows:*:* | all versions | Vulnerable | WatchGuard |
| cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:linux:*:* | before 1.5.1.25 | Vulnerable | Zscaler |
| cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:macos:*:* | before 4.2.0.282 | Vulnerable | Zscaler |
| cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:linux:*:* | 3.7 to before 3.7.0.134 | Vulnerable | Zscaler |
| cpe:2.3:a:zscaler:client_connector:-:*:*:*:*:windows:*:* | not specified by NVD | Vulnerable | Zscaler |
- cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:macos:*:* Versions all versions Vulnerable ·CyberArk Software, a Palo Alto Networks Company
- cpe:2.3:a:paloaltonetworks:globalprotect:*:*:*:*:*:windows:*:* Versions all versions Vulnerable ·CyberArk Software, a Palo Alto Networks Company
- cpe:2.3:a:citrix:secure_access_client:*:*:*:*:*:*:*:* Versions before 24.06.1 Vulnerable ·Citrix
- cpe:2.3:o:apple:iphone_os:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
- cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Apple
- cpe:2.3:a:citrix:secure_access_client:*:*:*:*:*:*:*:* Versions before 24.8.5 Vulnerable ·Citrix
- cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Linux
- cpe:2.3:a:f5:big-ip_access_policy_manager:*:*:*:*:*:*:*:* Versions 7.2.3 – 7.2.5; 15.1.0 – 15.1.10; 16.1.0 – 16.1.5; 17.1.0 – 17.1.2 Vulnerable ·F5
- cpe:2.3:a:watchguard:ipsec_mobile_vpn_client:*:*:*:*:*:macos:*:* Versions all versions Vulnerable ·WatchGuard
- cpe:2.3:a:watchguard:ipsec_mobile_vpn_client:*:*:*:*:*:windows:*:* Versions all versions Vulnerable ·WatchGuard
- cpe:2.3:a:watchguard:mobile_vpn_with_ssl:*:*:*:*:*:macos:*:* Versions all versions Vulnerable ·WatchGuard
- cpe:2.3:a:watchguard:mobile_vpn_with_ssl:*:*:*:*:*:windows:*:* Versions all versions Vulnerable ·WatchGuard
- cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:linux:*:* Versions before 1.5.1.25 Vulnerable ·Zscaler
- cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:macos:*:* Versions before 4.2.0.282 Vulnerable ·Zscaler
- cpe:2.3:a:zscaler:client_connector:*:*:*:*:*:linux:*:* Versions 3.7 to before 3.7.0.134 Vulnerable ·Zscaler
- cpe:2.3:a:zscaler:client_connector:-:*:*:*:*:windows:*:* Versions not specified by NVD Vulnerable ·Zscaler
Remediation
Red Hat 3 advisories
- RHSA-2025:16411 Released 2025-09-23 · Red Hat rating ModerateNetworkManager security update
- Red Hat CodeReady Linux Builder EUS (v.9.4) NetworkManager-libnm-devel-1:1.46.0-34.el9_4
- Red Hat Enterprise Linux AppStream EUS (v.9.4) NetworkManager-cloud-setup-1:1.46.0-34.el9_4, NetworkManager-config-connectivity-redhat-1:1.46.0-34.el9_4, NetworkManager-dispatcher-routing-rules-1:1.46.0-34.el9_4 +2
- Red Hat Enterprise Linux BaseOS EUS (v.9.4) NetworkManager-1:1.46.0-34.el9_4, NetworkManager-adsl-1:1.46.0-34.el9_4, NetworkManager-bluetooth-1:1.46.0-34.el9_4 +7
- RHSA-2025:0377 Released 2025-01-16 · Red Hat rating ModerateSecurity and bug fixes for NetworkManager
- Red Hat CodeReady Linux Builder (v. 9) NetworkManager-libnm-devel-1:1.48.10-5.el9_5
- Red Hat Enterprise Linux AppStream (v. 9) NetworkManager-cloud-setup-1:1.48.10-5.el9_5, NetworkManager-config-connectivity-redhat-1:1.48.10-5.el9_5, NetworkManager-dispatcher-routing-rules-1:1.48.10-5.el9_5 +2
- Red Hat Enterprise Linux BaseOS (v. 9) NetworkManager-1:1.48.10-5.el9_5, NetworkManager-adsl-1:1.48.10-5.el9_5, NetworkManager-bluetooth-1:1.48.10-5.el9_5 +7
- RHSA-2025:0288 Released 2025-01-13 · Red Hat rating ModerateBug fix of NetworkManager
- Red Hat Enterprise Linux AppStream (v. 8) NetworkManager-cloud-setup-1:1.40.16-18.el8_10
- Red Hat Enterprise Linux BaseOS (v. 8) NetworkManager-1:1.40.16-18.el8_10, NetworkManager-adsl-1:1.40.16-18.el8_10, NetworkManager-bluetooth-1:1.40.16-18.el8_10 +11
- Red Hat Enterprise Linux CRB (v. 8) NetworkManager-libnm-devel-1:1.40.16-18.el8_10
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:0377 |
| Red Hat CodeReady Linux Builder EUS (v.9.4) | Fixed | RHSA-2025:16411 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2025:0288 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:0377 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:16411 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2025:0288 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:0377 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.4) | Fixed | RHSA-2025:16411 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2025:0288 |
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2024-3661
- 2026-10-03 Alias added: GHSA-jcv7-6v4q-4m7x
References
Exploit 5
- https://tunnelvisionbug.com/
- 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://www.zscaler.com/blogs/security-research/cve-2024-3661-k-tunnelvision-exposes-vpn-bypass-vulnerability
- https://www.theregister.com/2024/05/07/vpn_tunnelvision_dhcp/
Advisory 8
- https://www.leviathansecurity.com/research/tunnelvision
- https://mullvad.net/en/blog/evaluating-the-impact-of-tunnelvision
- 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
Other 7
- https://datatracker.ietf.org/doc/html/rfc2131#section-7
- https://datatracker.ietf.org/doc/html/rfc3442#section-7
- https://news.ycombinator.com/item?id=40279632
- https://issuetracker.google.com/issues/263721377
- 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
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- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
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- TI-2004-02631 The MD5 Message-Digest Algorithm is not collision resistant, which makes it easier for… CVSS 3.1CRITICAL 9.8
- TI-2024-03351 RADIUS Protocol under RFC2865 is vulnerable to forgery attacks. CVSS 3.1CRITICAL 9.0
- TI-2020-08191 IP-in-IP protocol allows a remote, unauthenticated attacker to route arbitrary network traffic CVSS 3.1MEDIUM 5.3
- TI-2016-08218 An issue was discovered in the IPv6 protocol specification, related to ICMP Packet Too… CVSS 3.0HIGH 8.6
Sources
- CVE-2024-3661 · CVE Program
- CVE-2024-3661 · NVD
- FIRST EPSS
- GHSA-jcv7-6v4q-4m7x · GitHub Advisory Database · CC BY 4.0
- CVE-2024-3661 · Red Hat security data · CC BY 4.0
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