CVE-2020-1657 | Junos OS: SRX Series: An attacker sending spoofed packets to IPSec peers may cause a Denial of Service.

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.

Published: 2020-10-16 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-1657 is rated Moderate Risk (54/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.27%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-1657

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.39% 1.27% +0.88%
2 2025-03-30 0.46% 0.39% -0.08%
3 2025-03-29 — 0.46% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-1657

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-1657

Affected software / configurations for CVE-2020-1657

Vendor Product Version Raw CPE
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:-:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d10:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d15:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d20:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d25:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d30:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d35:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d40:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d45:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d50:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d51:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d55:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d60:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d65:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d70:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d75:*:*:*:*:*:*
juniper junos 12.3x48 cpe:2.3:o:juniper:junos:12.3x48:d80:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:-:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d10:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d100:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d110:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d120:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d130:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d140:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d15:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d150:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d160:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d170:*:*:*:*:*:*
juniper junos 15.1x49 cpe:2.3:o:juniper:junos:15.1x49:d180:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:-:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s1:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s2:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s4:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s5:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s6:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r1-s7:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s1:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s10:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s2:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s3:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s4:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s5:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s6:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s7:*:*:*:*:*:*
juniper junos 17.4 cpe:2.3:o:juniper:junos:17.4:r2-s8:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:-:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r1:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r2:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r2-s1:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r2-s2:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r2-s4:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s1:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s2:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s3:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s4:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s6:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s7:*:*:*:*:*:*
juniper junos 18.1 cpe:2.3:o:juniper:junos:18.1:r3-s8:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:-:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r1:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r1:-:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r1-s3:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r1-s4:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r1-s5:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s1:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s2:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s3:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s4:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s5:*:*:*:*:*:*
juniper junos 18.2 cpe:2.3:o:juniper:junos:18.2:r2-s6:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:-:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:r1:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:r1-s1:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:r1-s2:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:r1-s3:*:*:*:*:*:*
juniper junos 18.3 cpe:2.3:o:juniper:junos:18.3:r1-s5:*:*:*:*:*:*

References for CVE-2020-1657

URL Tags
https://kb.juniper.net/JSA11050 Vendor Advisory
cvelogic Threat Intelligence