CVE-2025-41731

Root access via timestamp-seeded debug password

Published Nov 10, 2025 · Updated Nov 10, 2025

Weak password generation in JUMO variTRON firmware before 9.0.2.5 allows local users to gain root access through the debug interface. The generator seeds its PRNG with the current Unix timestamp, making the debug password predictable to an attacker who knows its creation timeframe. Exploitation requires an authorized user to enable the debug interface; it exposes root access over UART and SSH only until the next reboot.

CVSS severity7.4
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Weak password generation in JUMO variTRON firmware before 9.0.2.5 allows local users to gain root access through the debug interface. The generator seeds its PRNG with the current Unix timestamp, making the debug password predictable to an attacker who knows its creation timeframe. Exploitation requires an authorized user to enable the debug interface; it exposes root access over UART and SSH only until the next reboot.

The record

CVE
CVE-2025-41731
Published
Nov 10, 2025
Updated
Nov 10, 2025
Vendor
JUMO
Product
JUMO variTRON 300
Classifications
CWE-338, T1110.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 10, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0.0.0 <9.0.2.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

JUMO · JUMO variTRON 300version=0.0.0.0 <9.0.2.5
JUMO · JUMO variTRON 500version=0.0.0.0 <9.0.2.5
JUMO · JUMO variTRON 500 touchversion=0.0.0.0 <9.0.2.5

Published CVSS scores

7.4CERT@VDECVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-338Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
T1110.001Password Guessing

Public exploit references

No public exploit references are available in this record.

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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