CVE-2020-1630

Privilege escalation via TOCTOU configuration race

Published Apr 8, 2020 · Updated Sep 16, 2024

Privilege escalation in Juniper Networks Junos OS allows local users with shell access to make unauthorized configuration changes. The vendor identifies a time-of-check/time-of-use race in privilege and access-control handling but does not disclose the affected process or operation. Exploitation requires a low-privileged authenticated shell account and a dual Routing Engine, Virtual Chassis, or high-availability cluster; standalone systems are unaffected.

CVSS severity5.0
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Juniper Networks Junos OS allows local users with shell access to make unauthorized configuration changes. The vendor identifies a time-of-check/time-of-use race in privilege and access-control handling but does not disclose the affected process or operation. Exploitation requires a low-privileged authenticated shell account and a dual Routing Engine, Virtual Chassis, or high-availability cluster; standalone systems are unaffected.

The record

CVE
CVE-2020-1630
Published
Apr 8, 2020
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-264, CWE-367, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2020CVE 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

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=12.3 <12.3R12-S14
  2. Affected versionversion=12.3X48 <12.3X48-D86, 12.3X48-D90
  3. Affected versionversion=14.1X53 <14.1X53-D51
  4. Affected versionversion=15.1 <15.1R7-S6
  5. Affected versionversion=15.1X49 <15.1X49-D181, 15.1X49-D190
  6. Affected versionversion=15.1X53 <15.1X53-D592
  7. Affected versionversion=16.1 <16.1R4-S13, 16.1R7-S6
  8. Affected versionversion=16.2 <16.2R2-S10
  9. Affected versionversion=17.1 <17.1R2-S11, 17.1R3-S1
  10. Affected versionversion=17.2 <17.2R1-S9, 17.2R3-S3
  11. Affected versionversion=17.3 <17.3R3-S6
  12. Affected versionversion=17.4 <17.4R2-S6, 17.4R3
  13. Affected versionversion=18.1 <18.1R3-S7
  14. Affected versionversion=18.2 <18.2R2-S5, 18.2R3-S1 changes=[{"at":"18.2X75-D12, 18.2X75-D33, 18.2X75-D420, 18.2X75-D60,18.2X75-D411","status":"unaffected"}]
  15. Affected versionversion=18.3 <18.3R1-S5, 18.3R2-S1, 18.3R3
  16. Affected versionversion=18.4 <18.4R1-S4, 18.4R2-S1, 18.4R3
  17. Affected versionversion=19.1 <19.1R1-S2, 19.1R2
  18. Affected versionversion=19.2 <19.2R1-S1, 19.2R2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Juniper Networks · Junos OSversion=12.3 <12.3R12-S14; version=12.3X48 <12.3X48-D86, 12.3X48-D90; version=14.1X53 <14.1X53-D51; version=15.1 <15.1R7-S6; version=15.1X49 <15.1X49-D181, 15.1X49-D190; version=15.1X53 <15.1X53-D592; version=16.1 <16.1R4-S13, 16.1R7-S6; version=16.2 <16.2R2-S10; version=17.1 <17.1R2-S11, 17.1R3-S1; version=17.2 <17.2R1-S9, 17.2R3-S3; version=17.3 <17.3R3-S6; version=17.4 <17.4R2-S6, 17.4R3; version=18.1 <18.1R3-S7; version=18.2 <18.2R2-S5, 18.2R3-S1 changes=[{"at":"18.2X75-D12, 18.2X75-D33, 18.2X75-D420, 18.2X75-D60,18.2X75-D411","status":"unaffected"}]; version=18.3 <18.3R1-S5, 18.3R2-S1, 18.3R3; version=18.4 <18.4R1-S4, 18.4R2-S1, 18.4R3; version=19.1 <19.1R1-S2, 19.1R2; version=19.2 <19.2R1-S1, 19.2R2

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:N
5.0Juniper Networks, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-264Permissions, Privileges, and Access Controls
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1068Exploitation for Privilege Escalation

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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