CVE-2020-1625

Service interruption via interface-flap kernel memory leak

Published Apr 8, 2020 · Updated Sep 17, 2024

Memory leak in the Junos OS kernel allows remote attackers to interrupt services by repeatedly flapping an IRB underlay interface. Kernel temporary-memory allocations are not released when Integrated Routing and Bridging uses multiple physical underlay interfaces and one interface flaps, so outstanding allocation requests continually rise. The affected configuration and adjacent-network access allow kernel-memory exhaustion to impair running daemons for an extended service interruption.

CVSS severity6.5
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Junos OS kernel allows remote attackers to interrupt services by repeatedly flapping an IRB underlay interface. Kernel temporary-memory allocations are not released when Integrated Routing and Bridging uses multiple physical underlay interfaces and one interface flaps, so outstanding allocation requests continually rise. The affected configuration and adjacent-network access allow kernel-memory exhaustion to impair running daemons for an extended service interruption.

The record

CVE
CVE-2020-1625
Published
Apr 8, 2020
Updated
Sep 17, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-401, CWE-400, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2020CVE 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=16.1 <16.1R7-S6
  2. Affected versionversion=17.1 <17.1R2-S11, 17.1R3-S1
  3. Affected versionversion=17.2 <17.2R2-S8, 17.2R3-S3
  4. Affected versionversion=17.2X75 <17.2X75-D44
  5. Affected versionversion=17.3 <17.3R2-S5, 17.3R3-S6
  6. Affected versionversion=17.4 <17.4R2-S5, 17.4R3
  7. Affected versionversion=18.1 <18.1R3-S7
  8. Affected versionversion=18.2 <18.2R2-S5, 18.2R3
  9. Affected versionversion=18.2X75 <18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60
  10. Affected versionversion=18.3 <18.3R1-S5, 18.3R2-S3, 18.3R3
  11. Affected versionversion=18.4 <18.4R2-S2, 18.4R3
  12. Affected versionversion=19.1 <19.1R1-S3, 19.1R2
  13. Affected versionversion=19.2 <19.2R1-S3, 19.2R2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=16.1 <16.1R7-S6; version=17.1 <17.1R2-S11, 17.1R3-S1; version=17.2 <17.2R2-S8, 17.2R3-S3; version=17.2X75 <17.2X75-D44; version=17.3 <17.3R2-S5, 17.3R3-S6; version=17.4 <17.4R2-S5, 17.4R3; version=18.1 <18.1R3-S7; version=18.2 <18.2R2-S5, 18.2R3; version=18.2X75 <18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60; version=18.3 <18.3R1-S5, 18.3R2-S3, 18.3R3; version=18.4 <18.4R2-S2, 18.4R3; version=19.1 <19.1R1-S3, 19.1R2; version=19.2 <19.2R1-S3, 19.2R2

Published CVSS scores

3.3NIST NVDAV:A/AC:L/Au:N/C:N/I:N/A:P
6.5Juniper NetworksCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.5NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

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

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

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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