Skip to main content
No exploitation reported

CVE-2020-1627

No exploitation reported by the sources we read.

  • Published2020-04-08

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in Juniper Networks Junos OS on vMX and MX150 devices may allow an attacker to cause a Denial of Service (DoS) by sending specific packets requiring special processing in microcode that the flow cache can't handle, causing the riot forwarding daemon to crash. By continuously sending the same specific packets, an attacker can repeatedly crash the riot process causing a sustained Denial of Service. Flow cache is specific to vMX based products and the MX150, and is enabled by default in performance mode. This issue can only be triggered by traffic destined to the device. Transit traffic will not cause the riot daemon to crash. When the issue occurs, a core dump and riot log file entry are generated. For example: /var/crash/core.J-UKERN.mpc0.1557255993.3864.gz /home/pfe/RIOT logs: fpc0 riot[1888]: PANIC in lu_reorder_send_packet_postproc(): fpc0 riot[6655]: PANIC in lu_reorder_send_packet_postproc(): This issue affects Juniper Networks Junos OS: 18.1 versions prior to 18.1R3 on vMX and MX150; 18.2 versions prior to 18.2R3 on vMX and MX150; 18.2X75 versions prior to 18.2X75-D60 on vMX and MX150; 18.3 versions prior to 18.3R3 on vMX and MX150; 18.4 versions prior to 18.4R2 on vMX and MX150; 19.1 versions prior to 19.1R2 on vMX and MX150. This issue does not affect Junos OS versions prior to 18.1R1.

Timeline

dates in UTC
  1. 2020-04-0820:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-1627?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-1627?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Juniper junosversion to verify
BranchAffectedFixed in
18.1= 18.1no fix published
18.2= 18.2no fix published
18.2= 18.2x75no fix published
18.3= 18.3no fix published
18.4= 18.4no fix published
19.1= 19.1no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CNACVSS 3.17.5read 2026-10-23
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • FIRST EPSSEPSS score1.3 %2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2020-04-08
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-1627?

A vulnerability in Juniper Networks Junos OS on vMX and MX150 devices may allow an attacker to cause a Denial of Service (DoS) by sending specific packets requiring special processing in microcode that the flow cache can't handle, causing the riot forwarding daemon to crash. By continuously sending the same specific packets, an attacker can repeatedly crash the riot process causing a sustained Denial of Service. Flow cache is specific to vMX based products and the MX150, and is enabled by default in performance mode. This issue can only be triggered by traffic destined to the device. Transit traffic will not cause the riot daemon to crash. When the issue occurs, a core dump and riot log file entry are generated. For example: /var/crash/core.J-UKERN.mpc0.1557255993.3864.gz /home/pfe/RIOT logs: fpc0 riot[1888]: PANIC in lu_reorder_send_packet_postproc(): fpc0 riot[6655]: PANIC in lu_reorder_send_packet_postproc(): This issue affects Juniper Networks Junos OS: 18.1 versions prior to 18.1R3 on vMX and MX150; 18.2 versions prior to 18.2R3 on vMX and MX150; 18.2X75 versions prior to 18.2X75-D60 on vMX and MX150; 18.3 versions prior to 18.3R3 on vMX and MX150; 18.4 versions prior to 18.4R2 on vMX and MX150; 19.1 versions prior to 19.1R2 on vMX and MX150. This issue does not affect Junos OS versions prior to 18.1R1.

Is CVE-2020-1627 actively exploited?

Active exploitation of CVE-2020-1627 has not been confirmed. Its EPSS score was 1.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-1627?

CVE-2020-1627 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

No credit card required · No monthly cap on website lookups · 250 API requests/month