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Fencer Intel
critical 9.8

CVE-2025-64097 json

NervesHub has Insufficient Token Entropy that Allows Authentication Bypass via Brute Force

published 9mo ago modified 4mo ago also EUVD-2025-206329

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

NervesHub is a web service that allows users to manage over-the-air (OTA) firmware updates of devices in the field. A vulnerability present starting in version 1.0.0 and prior to version 2.3.0 allowed attackers to brute-force user API tokens due to the predictable format of previously issued tokens. Tokens included user-identifiable components and were not cryptographically secure, making them susceptible to guessing or enumeration. The vulnerability could have allowed unauthorized access to user accounts or API actions protected by these tokens. A fix is available in version 2.3.0 of NervesHub. This version introduces strong, cryptographically-random tokens using `:crypto.strong_rand_bytes/1`, hashing of tokens before database storage to prevent misuse even if the database is compromised, and context-aware token storage to distinguish between session and API tokens. There are no practical workarounds for this issue other than upgrading. In sensitive environments, as a temporary mitigation, firewalling access to the NervesHub server can help limit exposure until an upgrade is possible.

Patch / fix

  • nerves-hub nerveshub 2.3.0

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
9mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 4.0 9.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:H
CNA 4.0 9.5 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • nerves-hub nerves_hub_web

Classification

Weakness
  • CWE-330 Use of Insufficiently Random Values

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.