CVE-2021-0248Network attack vector

Instance takeover via hard-coded administrative credentials

Published Apr 22, 2021 · Updated Sep 16, 2024

Hard-coded credentials in Juniper Networks Junos OS before 19.1R1 on NFX Series devices allow remote attackers to take over an NFX instance. Juniper has not published the credential's location, value, or the administrative authentication path that accepts it. Administrative-interface reachability is sufficient for unauthenticated control of the affected deployment, while other Juniper platforms are unaffected.

CVSS severity10.0
Critical
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hard-coded credentials in Juniper Networks Junos OS before 19.1R1 on NFX Series devices allow remote attackers to take over an NFX instance. Juniper has not published the credential's location, value, or the administrative authentication path that accepts it. Administrative-interface reachability is sufficient for unauthenticated control of the affected deployment, while other Juniper platforms are unaffected.

The record

CVE
CVE-2021-0248
Published
Apr 22, 2021
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-798, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record 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=unspecified <19.1R1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=unspecified <19.1R1

Published CVSS scores

10.0Juniper NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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