Junos OS and Junos OS Evolved: RPD crash due to specific BGP UPDATE packets

published 2020-07-17 6y ago modified 2026-06-17 4mo ago also EUVD-2020-12509

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits: 0; none known

On Juniper Networks Junos OS and Junos OS Evolved devices, the receipt of a specific BGP UPDATE packet causes an internal counter to be incremented incorrectly, which over time can lead to the routing protocols process (RPD) crash and restart. This issue affects both IBGP and EBGP multihop deployment in IPv4 or IPv6 network. This issue affects: Juniper Networks Junos OS: 17.2X75 versions prior to 17.2X75-D105.19; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S10, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S4; 18.2X75 versions prior to 18.2X75-D13, 18.2X75-D411.1, 18.2X75-D420.18, 18.2X75-D52.3, 18.2X75-D60; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3-S2; 19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S2, 19.3R3; 19.4 versions prior to 19.4R1-S2, 19.4R2. Juniper Networks Junos OS Evolved: any releases prior to 20.1R2-EVO. This issue does not affect Juniper Networks Junos OS releases prior to 17.3R1.

Patch / fix

fixed in 2

Juniper Networks Junos OS 17.2X75-D105.19, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S4, 18.2X75-D13, 18.2X75-D411.1, 18.2X75-D420.18, 18.2X75-D52.3, 18.2X75-D60, 18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S2, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R1-S5, 19.2R2, 19.3R2-S2, 19.3R3, 19.4R1-S2, 19.4R2
Juniper Networks Junos OS Evolved 20.1R2-EVO

Is CVE-2020-1644 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

1.28% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

Juniper Networks Junos OS
Juniper Networks Junos OS Evolved

Classification

Weakness

CWE-703 Improper Check or Handling of Exceptional Conditions
CWE-20 Improper Input Validation

References

kb.juniper.net /JSA11032
vendor-advisory

Sources

CVE List CVE-2020-1644
NVD CVE-2020-1644

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.