CVE-2021-0235

Cross-tenant traffic redirection via overbroad administrator permissions

Published Apr 22, 2021 · Updated Sep 17, 2024

Improper permissions in Juniper Networks Junos OS on affected SRX and vSRX releases allow local users to redirect tenant traffic. The tenant-services permission scheme lets tenant system administrators modify device-wide traffic management instead of confining changes to their own tenant. Reachability requires tenant services and tenant administrator access; traffic can cross isolation boundaries and affect other tenants and the provider.

CVSS severity7.3
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper permissions in Juniper Networks Junos OS on affected SRX and vSRX releases allow local users to redirect tenant traffic. The tenant-services permission scheme lets tenant system administrators modify device-wide traffic management instead of confining changes to their own tenant. Reachability requires tenant services and tenant administrator access; traffic can cross isolation boundaries and affect other tenants and the provider.

The record

CVE
CVE-2021-0235
Published
Apr 22, 2021
Updated
Sep 17, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-276, T1562.004
Attack vector
local
Privileges
admin

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=18.3R1 <18.3*
  2. Affected versionversion=18.4R1 <18.4*
  3. Affected versionversion=19.1R1 <19.1*
  4. Affected versionversion=19.2 <19.2R1-S6, 19.2R3-S2
  5. Affected versionversion=19.3 <19.3R3-S2
  6. Affected versionversion=19.4 <19.4R2-S4, 19.4R3-S2
  7. Affected versionversion=20.1 <20.1R2, 20.1R3
  8. Affected versionversion=20.2 <20.2R2-S1, 20.2R3
  9. Affected versionversion=20.3 <20.3R1-S2, 20.3R2
  10. Affected versionversion=20.4 <20.4R1, 20.4R2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Juniper Networks · Junos OSversion=18.3R1 <18.3*; version=18.4R1 <18.4*; version=19.1R1 <19.1*; version=19.2 <19.2R1-S6, 19.2R3-S2; version=19.3 <19.3R3-S2; version=19.4 <19.4R2-S4, 19.4R3-S2; version=20.1 <20.1R2, 20.1R3; version=20.2 <20.2R2-S1, 20.2R3; version=20.3 <20.3R1-S2, 20.3R2; version=20.4 <20.4R1, 20.4R2

Published CVSS scores

4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.3Juniper NetworksCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:L/I:H/A:L

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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1562.004Impair Defenses: Disable or Modify System Firewall

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo