No exploitation reported

CVE-2020-1657

No exploitation reported by the sources we read.

Published2020-10-16
WeaknessCWE-408

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

On SRX Series devices, a vulnerability in the key-management-daemon (kmd) daemon of Juniper Networks Junos OS allows an attacker to spoof packets targeted to IPSec peers before a security association (SA) is established thereby causing a failure to set up the IPSec channel. Sustained receipt of these spoofed packets can cause a sustained Denial of Service (DoS) condition. This issue affects IPv4 and IPv6 implementations. This issue affects Juniper Networks Junos OS on SRX Series: 12.3X48 versions prior to 12.3X48-D90; 15.1X49 versions prior to 15.1X49-D190; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S9; 18.2 versions prior to 18.2R3; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R1-S6, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S4, 19.1R2. This issue does not affect 12.3 or 15.1 releases which are non-SRX Series releases.

Timeline

dates in UTC

2020-10-1621:15CVE 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-2020-1657?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-1657?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Juniper junos

Branch	Affected	Fixed in	Source
12.3	= 12.3x48	no fix published	NVD
15.1	= 15.1x49	no fix published	NVD
17.4	= 17.4	no fix published	NVD
18.1	= 18.1	no fix published	NVD
18.2	= 18.2	no fix published	NVD
18.3	= 18.3	no fix published	NVD
18.4	= 18.4	no fix published	NVD
19.1	= 19.1	no fix published	NVD

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

Fix

Advisories and patches

kb.juniper.netVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-408read 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: 2020-10-16
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-1657?

Is CVE-2020-1657 actively exploited?

Active exploitation of CVE-2020-1657 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-2020-1657?

CVE-2020-1657 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.

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