Traffic spoofing via unauthenticated packet decapsulation
Published Feb 5, 2025 · Updated Nov 3, 2025
Source-validation failure in IETF Generic Routing Encapsulation STD 1 allows remote attackers to route spoofed traffic through exposed interfaces. Implementations accept and decapsulate GRE or GRE6 packets without authenticating or restricting the outer packet source, then forward attacker-controlled inner packets. An internet-reachable tunnel endpoint that accepts packets from arbitrary sources can act as a one-way proxy, bypass network access controls, expose private networks, or amplify denial-of-service traffic.
Summary
What happened
Source-validation failure in IETF Generic Routing Encapsulation STD 1 allows remote attackers to route spoofed traffic through exposed interfaces. Implementations accept and decapsulate GRE or GRE6 packets without authenticating or restricting the outer packet source, then forward attacker-controlled inner packets. An internet-reachable tunnel endpoint that accepts packets from arbitrary sources can act as a one-way proxy, bypass network access controls, expose private networks, or amplify denial-of-service traffic.
The record
- CVE
- CVE-2024-7595
- Published
- Feb 5, 2025
- Updated
- Nov 3, 2025
- Vendor
- Internet Engineering Task Force
- Product
- Generic Routing Encapsulation (GRE)
- Classifications
- CWE-290, T1090.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 5, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=STD 1
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- TunnelTesterfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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