CVE-2025-24356

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Source
https://cve.org/CVERecord?id=CVE-2025-24356
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-24356.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-24356
Aliases
  • GHSA-pggg-vpfv-4rcv
Downstream
Published
2025-01-27T17:31:38.541Z
Modified
2026-02-11T02:34:42.727078Z
Severity
  • 6.9 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
UDP traffic amplification via fastd's fast reconnect feature
Details

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.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/24xxx/CVE-2025-24356.json",
    "cwe_ids": [
        "CWE-405"
    ],
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/neocturne/fastd

Affected ranges

Type
GIT
Repo
https://github.com/neocturne/fastd
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
e0d59850b680e8fd9d39bf1edff2062cc5e27c6f

Affected versions

v0.*
v0.1
v0.1-rc1
v0.1-rc2
v0.1-rc3
v0.1-rc4
v0.2
v0.3
v0.4
v0.4-rc1
v0.4-rc10
v0.4-rc11
v0.4-rc12
v0.4-rc13
v0.4-rc2
v0.4-rc3
v0.4-rc4
v0.4-rc5
v0.4-rc6
v0.4-rc7
v0.4-rc8
v0.4-rc9
v0.5
v0.5-rc1
v0.5-rc2
v0.5-rc3
v0.5-rc4
Other
v10
v11
v12
v13
v14
v15
v16
v17
v18
v19
v20
v21
v22
v6
v6-rc1
v7
v8
v9

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-24356.json"