Jumo: Predictable debug-interface password in variTRON series
A vulnerability was identified in the variTRON password generation algorithm of the debug-interface. The PRNG is initialized with the current Unix Timestamp, thus the resulting password is predictable. With the password root-access to the UART and ssh Interface can be gained. The impact is limited, since the debug-interface has to be actively enabled by an authorized user and will be deactivated automatically after the next reboot of the device.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-41731US | — | — | ||
A vulnerability was identified in the password generation algorithm when accessing the debug-interface. An unauthenticated local attacker with knowledge of the password generation… | ||||
references
External citations — patches, advisories, analysis.
remediations (2)
- Mitigation
Disable the debug interface to prevent unauthorized root-access to the ssh Interface. The debug interface of the ssh is deactivated after rebooting the system.
- Fixed
Update the affected products to version 9.0.2.5.
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