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Generic Routing EncapsulationApplication · Ietf

CVE-2024-7595

MEDIUM · 6.5 CVSS v3.1 Published 2025-02-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
GRE and GRE6 Protocols (RFC2784) do not validate or verify the source of a network packet allowing an attacker to spoof and route arbitrary traffic via an exposed network interface that can lead to spoofing, access control bypass, and other unexpected network behaviors. This can be considered similar to CVE-2020-10136.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

GRE and GRE6 protocols (RFC2784) lack source address validation, allowing attackers to spoof packets and route arbitrary traffic through exposed GRE tunnel interfaces, leading to access control bypass and other unexpected network behaviors.

MitigationRestrict GRE tunnel exposure to trusted networks via access control lists or network segmentation, and implement strict ingress filtering at network boundaries to mitigate spoofing attacks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Generic Routing EncapsulationApplication
Affected:all versions
Generic Routing Encapsulation6Application
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify active GRE tunnel interfaces
    Run 'ip tunnel show' or 'ip -6 tunnel show' on Linux, 'show interfaces tunnel' on Cisco IOS, or check system network config for GRE or GRE6 tunnel types
    Affected if Any GRE or GRE6 tunnel interface is present and active on the system
  2. Verify GRE tunnel source address configuration
    Examine the GRE tunnel configuration - on Linux use 'ip tunnel show' to list tunnel endpoints, or review the tunnel config files in /etc/sysconfig/network-scripts/ (RHEL/CentOS) or /etc/network/interfaces (Debian)
    Affected if The tunnel is configured with a specific source address that is not validated against incoming packets, or no source validation mechanism is explicitly configured
  3. Check GRE protocol exposure to untrusted networks
    Review firewall rules (iptables, nftables, or network ACLs) to determine if protocol 47 (GRE) or the GRE tunnel endpoints are accessible from external/untrusted networks
    Affected if GRE traffic from untrusted sources is permitted through the firewall without source address filtering or ACL restrictions
  4. Assess ingress filtering on GRE traffic
    Examine network edge devices and host-based firewalls for any anti-spoofing filters or uRPF (unicast Reverse Path Forwarding) checks applied to GRE-encapsulated traffic
    Affected if No ingress filtering, anti-spoofing rules, or uRPF validation is configured for GRE traffic at network boundaries
  5. Confirm GRE kernel module or service status
    On Linux, check if the 'gre' or 'ip_gre' kernel module is loaded with 'lsmod | grep gre', or verify GRE support is compiled into the kernel
    Affected if GRE protocol support is enabled in the kernel or operating system (this is the baseline condition for all GRE implementations)

A system is affected if it has any active GRE or GRE6 tunnel interfaces and lacks source address validation or ingress filtering on the GRE traffic from untrusted sources.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Restrict GRE tunnel exposure to trusted networks via access control lists or network segmentation, and implement strict ingress filtering at network boundaries to mitigate spoofing attacks.

Fix this in Generic Routing Encapsulation Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,980
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-7595 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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