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CVE-2020-1637

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

High7.2EPSS 0.83%
Published
Updated
Reserved
Assigned by
juniper

Description

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.

Scores

CVSS scores of CVE-2020-1637, by who scored it
Scored byCVSSScoreVector
juniperCNA (assigner)3.1High7.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
NVDNVD · Modified3.1Medium6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS (exploitation in 30 days)
0.83% · top 42% of all CVEs (7 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.

Weakness

Affected products

  • Juniper Networks · Junos OS

    • affected 12.3X48 – < 12.3X48-D100
    • affected 15.1X49 – < 15.1X49-D210
    • affected 17.3 – < 17.3R2-S5, 17.3R3-S8
    • affected 17.4 – < 17.4R2-S9, 17.4R3-S1
    • affected 18.1 – < 18.1R3-S10
    • affected 18.2 – < 18.2R2-S7, 18.2R3-S3
    • affected 18.3 – < 18.3R1-S7, 18.3R3-S2
    • affected 18.4 – < 18.4R1-S6, 18.4R2-S4, 18.4R3-S1
    • affected 19.1 – < 19.1R1-S4, 19.1R2-S1, 19.1R3
    • affected 19.2 – < 19.2R1-S3, 19.2R2
    • affected 19.3 – < 19.3R2-S1, 19.3R3
    • affected 19.4 – < 19.4R1-S1, 19.4R2

What to do

Solution: The following software releases have been updated to resolve this specific issue: 12.3X48-D100, 15.1X49-D210, 16.1R7-S7, 17.3R2-S5, 17.3R3-S8, 17.4R2-S9, 17.4R3-S1, 18.1R3-S10, 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, 20.1R1, and all subsequent releases.

Workaround: To avoid this issue, the IP address configuration in the IC Server should be configured as IP address/netmask, rather than an IP address range. For example: configure 10.0.0.0/25 instead of 10.0.0.1-127.

Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

References (1)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated .