Junos OS: SRX Series: Unified Access Control (UAC) bypass vulnerability

published 2020-04-08 6y ago modified 2026-06-17 4mo ago also EUVD-2020-12503

cvss: 7.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

A vulnerability in Juniper Networks SRX Series device configured as a Junos OS Enforcer device may allow a user to access network resources that are not permitted by a UAC policy. This issue might occur when the IP address range configured in the Infranet Controller (IC) is configured as an IP address range instead of an IP address/netmask. See the Workaround section for more detail. The Junos OS Enforcer CLI settings are disabled by default. This issue affects Juniper Networks Junos OS on SRX Series: 12.3X48 versions prior to 12.3X48-D100; 15.1X49 versions prior to 15.1X49-D210; 17.3 versions prior to 17.3R2-S5, 17.3R3-S8; 17.4 versions prior to 17.4R2-S9, 17.4R3-S1; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S3; 18.3 versions prior to 18.3R1-S7, 18.3R3-S2; 18.4 versions prior to 18.4R1-S6, 18.4R2-S4, 18.4R3-S1; 19.1 versions prior to 19.1R1-S4, 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S3, 19.2R2; 19.3 versions prior to 19.3R2-S1, 19.3R3; 19.4 versions prior to 19.4R1-S1, 19.4R2.

Patch / fix

fixed in 1

Juniper Networks Junos OS 12.3X48-D100, 15.1X49-D210, 17.3R2-S5, 17.3R3-S8, 17.4R2-S9, 17.4R3-S1, 18.1R3-S10, 18.2R2-S7, 18.2R3-S3, 18.3R1-S7, 18.3R3-S2, 18.4R1-S6, 18.4R2-S4, 18.4R3-S1, 19.1R1-S4, 19.1R2-S1, 19.1R3, 19.2R1-S3, 19.2R2, 19.3R2-S1, 19.3R3, 19.4R1-S1, 19.4R2

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Exploit prediction

0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.2	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD	2.0	5.8	AV:N/AC:M/Au:N/C:P/I:P/A:N

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-288 Authentication Bypass Using an Alternate Path or Channel
CWE-287 Improper Authentication

References

kb.juniper.net /JSA11018
vendor-advisory

Sources

CVE List CVE-2020-1637
NVD CVE-2020-1637

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