Amplification Vulnerability in fastd VPN Daemon
CVE-2025-24356

6.9MEDIUM

Key Information:

Vendor

Neocturne

Status
Fastd
Vendor
CVE Published:
27 January 2025

What is CVE-2025-24356?

fastd, a VPN daemon known for tunneling IP packets, has a vulnerability that allows attackers to exploit the fast reconnect feature. By sending UDP packets with spoofed source addresses, an attacker can induce the fastd instance to initiate a handshake with an amplification factor of approximately 12-13 times. This behavior can facilitate Distributed Denial of Service (DDoS) attacks against targeted networks, making it essential for users to update to version 23 or later to mitigate this risk.

Affected Version(s)

fastd < 23

References

https://github.com/neocturne/fastd/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/neocturne/fastd/commit/1f233bee76b722c...
x_refsource_MISC
https://github.com/neocturne/fastd/commit/3940150e801d0c9...
x_refsource_MISC

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.