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CVE-2025-24356 Detail

Description

fastd is a VPN daemon which tunnels IP packets and Ethernet frames over UDP. When receiving a data packet from an unknown IP address/port combination, fastd will assume that one of its connected peers has moved to a new address and initiate a reconnect by sending a handshake packet. This "fast reconnect" avoids having to wait for a session timeout (up to ~90s) until a new connection is established. Even a 1-byte UDP packet just containing the fastd packet type header can trigger a much larger handshake packet (~150 bytes of UDP payload). Including IPv4 and UDP headers, the resulting amplification factor is roughly 12-13. By sending data packets with a spoofed source address to fastd instances reachable on the internet, this amplification of UDP traffic might be used to facilitate a Distributed Denial of Service attack. This vulnerability is fixed in v23.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 6.9 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/neocturne/fastd/commit/1f233bee76b722c0b3f9024f2c39c72e9f7e5843
https://github.com/neocturne/fastd/commit/3940150e801d0c91460491bec32cbcc5bbc89d5f
https://github.com/neocturne/fastd/commit/5f63fcfc18ae9cad023fa463b152d5e14192b5a8
https://github.com/neocturne/fastd/commit/9df7e516378441d2d17b89f9db5c27c8312d8f12
https://github.com/neocturne/fastd/commit/c1a07b3f2b9066c3713c68547da700b85d60f4f7
https://github.com/neocturne/fastd/commit/ce1b79b12dbfa796743b5f3a50789ade965b7023
https://github.com/neocturne/fastd/commit/d03a0a17347efb5293e42fde7d982781e90f14ef
https://github.com/neocturne/fastd/security/advisories/GHSA-pggg-vpfv-4rcv

Weakness Enumeration

CWE-ID CWE Name Source
CWE-405 Asymmetric Resource Consumption (Amplification) GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2025-24356
NVD Published Date:
01/27/2025
NVD Last Modified:
01/27/2025
Source:
GitHub, Inc.