vde-2025-086
HIGH CVSS 7.4 csaf_jumogmbhcokg
Description
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.
Timeline
- Published
- 2025-11-10 11:00 UTC
- Last Modified
- 2025-11-10
CVSS Details
CVSS details not available.
Affected Products
No product information available.
Weaknesses (CWE)
References
No references available.
Linked Vulnerabilities
No linked vulnerabilities found.
{
"document": {
"acknowledgments": [
{
"organization": "CERT@VDE",
"summary": "coordination",
"urls": [
"https://certvde.com"
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],
"aggregate_severity": {
"namespace": "https://www.first.org/cvss/v3.1/specification-document#Qualitative-Severity-Rating-Scale",
"text": "High"
},
"category": "csaf_security_advisory",
"csaf_version": "2.0",
"distribution": {
"tlp": {
"label": "WHITE",
"url": "https://www.first.org/tlp/"
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},
"lang": "en-GB",
"notes": [
{
"category": "summary",
"text": "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.\nWith the password root-access to the UART and ssh Interface can be gained.\nThe 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.",
"title": "Summary"
},
{
"category": "description",
"text": "Unauthorized root-access to the UART and ssh Interface.",
"title": "Impact"
},
{
"category": "description",
"text": "Update the affected products to version 9.0.2.5. ",
"title": "Remediation"
},
{
"category": "description",
"text": "Disable the debug-interface to prevent unauthorized root-access to the UART and ssh Interface.",
"title": "Mitigation"
}
],
"publisher": {
"category": "vendor",
"contact_details": "psirt@jumo.net",
"name": "JUMO GmbH & Co. KG",
"namespace": "https://www.jumo.de"
},
"references": [
{
"category": "external",
"summary": "Jumo PSIRT",
"url": "https://www.jumo.de"
},
{
"category": "external",
"summary": "CERT@VDE Security Advisories for Jumo",
"url": "https://certvde.com/de/advisories/vendor/jumo/"
},
{
"category": "self",
"summary": "VDE-2025-086: Jumo: Predictable debug-interface password in variTRON series - HTML",
"url": "https://certvde.com/en/advisories/VDE-2025-086"
},
{
"category": "self",
"summary": "VDE-2025-086: Jumo: Predictable debug-interface password in variTRON series - CSAF",
"url": "https://jumo.csaf-tp.certvde.com/.well-known/csaf/white/2025/vde-2025-086.json"
}
],
"title": "Jumo: Predictable debug-interface password in variTRON series",
"tracking": {
"aliases": [
"VDE-2025-086"
],
"current_release_date": "2025-11-10T11:00:00.000Z",
"generator": {
"date": "2025-11-04T13:31:42.418Z",
"engine": {
"name": "Secvisogram",
"version": "2.5.38"
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},
"id": "VDE-2025-086",
"initial_release_date": "2025-11-10T11:00:00.000Z",
"revision_history": [
{
"date": "2025-11-10T11:00:00.000Z",
"number": "1.0.0",
"summary": "Release version."
}
],
"status": "final",
"version": "1.0.0"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"branches": [
{
"category": "product_name",
"name": "variTRON300",
"product": {
"name": "variTRON300",
"product_id": "CSAFPID-11001"
}
},
{
"category": "product_name",
"name": " variTRON500",
"product": {
"name": "variTRON500",
"product_id": "CSAFPID-11002"
}
},
{
"category": "host_name",
"name": "variTRON500 touch",
"product": {
"name": "variTRON500 touch",
"product_id": "CSAFPID-11003"
}
}
],
"category": "product_family",
"name": "Hardware"
},
{
"branches": [
{
"category": "product_version_range",
"name": "<9.0.2.5. ",
"product": {
"name": "Firmware <9.0.2.5. ",
"product_id": "CSAFPID-21001"
}
},
{
"category": "product_version",
"name": "9.0.2.5. ",
"product": {
"name": "Firmware 9.0.2.5. ",
"product_id": "CSAFPID-22001"
}
}
],
"category": "product_family",
"name": "Firmware"
}
],
"category": "vendor",
"name": "Jumo"
}
],
"product_groups": [
{
"group_id": "CSAFGID-0001",
"product_ids": [
"CSAFPID-31001",
"CSAFPID-31002",
"CSAFPID-31003"
],
"summary": "Affected products."
},
{
"group_id": "CSAFGID-0002",
"product_ids": [
"CSAFPID-32001",
"CSAFPID-32002",
"CSAFPID-32003"
],
"summary": "Fixed products."
}
],
"relationships": [
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware <9.0.2.5. installed on variTRON300",
"product_id": "CSAFPID-31001"
},
"product_reference": "CSAFPID-21001",
"relates_to_product_reference": "CSAFPID-11001"
},
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware <9.0.2.5. installed on variTRON500",
"product_id": "CSAFPID-31002"
},
"product_reference": "CSAFPID-21001",
"relates_to_product_reference": "CSAFPID-11002"
},
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware <9.0.2.5. installed on variTRON500 touch",
"product_id": "CSAFPID-31003"
},
"product_reference": "CSAFPID-21001",
"relates_to_product_reference": "CSAFPID-11003"
},
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware 9.0.2.5. installed on variTRON300",
"product_id": "CSAFPID-32001"
},
"product_reference": "CSAFPID-22001",
"relates_to_product_reference": "CSAFPID-11001"
},
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware 9.0.2.5. installed on variTRON500",
"product_id": "CSAFPID-32002"
},
"product_reference": "CSAFPID-22001",
"relates_to_product_reference": "CSAFPID-11002"
},
{
"category": "installed_on",
"full_product_name": {
"name": "Firmware 9.0.2.5. installed on variTRON500 touch",
"product_id": "CSAFPID-32003"
},
"product_reference": "CSAFPID-22001",
"relates_to_product_reference": "CSAFPID-11003"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2025-41731",
"cwe": {
"id": "CWE-338",
"name": "Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)"
},
"notes": [
{
"category": "description",
"text": "A vulnerability was identified in the password generation algorithm when accessing the debug-interface. An unauthenticated local attacker with knowledge of the password generation timeframe might be able to brute force the password in a timely manner and thus gain root access to the device if the debug interface is still enabled.",
"title": "CVE Description"
}
],
"product_status": {
"fixed": [
"CSAFPID-32001",
"CSAFPID-32002",
"CSAFPID-32003"
],
"known_affected": [
"CSAFPID-31001",
"CSAFPID-31002",
"CSAFPID-31003"
]
},
"references": [
{
"category": "external",
"summary": "Advisory: VDE-2025-015",
"url": "https://certvde.com/en/advisories/VDE-2025-015/"
}
],
"remediations": [
{
"category": "vendor_fix",
"details": "Update the affected products to version 9.0.2.5. ",
"group_ids": [
"CSAFGID-0001"
]
},
{
"category": "mitigation",
"details": "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.",
"group_ids": [
"CSAFGID-0001"
]
}
],
"scores": [
{
"cvss_v3": {
"attackComplexity": "HIGH",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.4,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"environmentalScore": 7.4,
"environmentalSeverity": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"temporalScore": 7.4,
"temporalSeverity": "HIGH",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"products": [
"CSAFPID-31001",
"CSAFPID-31002",
"CSAFPID-31003"
]
}
],
"title": "Jumo: Insufficient entropy in PRNG may lead to root access"
}
]
}