CVE-2021-0231Network attack vector

Authenticated file disclosure via J-Web path traversal

Published Apr 22, 2021 · Updated Sep 17, 2024

Path traversal in J-Web on Juniper Networks Junos OS for SRX and vSRX allows remote authenticated users to read sensitive system files. J-Web fails to confine an authenticated file request to its intended directory, allowing traversal sequences to resolve paths to sensitive files. Exposure requires J-Web through the web-management HTTP or HTTPS configuration and a valid J-Web account; published details do not identify the affected handler or parameter.

CVSS severity6.5
Medium
EPSS probability1.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in J-Web on Juniper Networks Junos OS for SRX and vSRX allows remote authenticated users to read sensitive system files. J-Web fails to confine an authenticated file request to its intended directory, allowing traversal sequences to resolve paths to sensitive files. Exposure requires J-Web through the web-management HTTP or HTTPS configuration and a valid J-Web account; published details do not identify the affected handler or parameter.

The record

CVE
CVE-2021-0231
Published
Apr 22, 2021
Updated
Sep 17, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-22, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=19.3 <19.3R2-S6, 19.3R3-S1
  2. Affected versionversion=19.4 <19.4R2-S4, 19.4R3
  3. Affected versionversion=20.1 <20.1R1-S4, 20.1R2
  4. Affected versionversion=20.2 <20.2R1-S3, 20.2R2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Juniper Networks · Junos OSversion=19.3 <19.3R2-S6, 19.3R3-S1; version=19.4 <19.4R2-S4, 19.4R3; version=20.1 <20.1R1-S4, 20.1R2; version=20.2 <20.2R1-S3, 20.2R2

Published CVSS scores

6.5Juniper Networks, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
6.8NIST NVDAV:N/AC:L/Au:S/C:C/I:N/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System

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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