What is CVE-2021-31386?

CVE-2021-31386 is a medium-severity vulnerability in Juniper Junos, classified under Channel Accessible by Non-Endpoint. CVSS score: 5.3/10. Published 2021-10-19.

How severe is CVE-2021-31386?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Juniper Junos

CVE-2021-31386

A Protection Mechanism Failure vulnerability in the J-Web HTTP service of Juniper Networks Junos OS allows a remote unauthenticated attacker to perform Person-in-the-Middle (PitM) attacks against the device. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S20; 15.1 versions prior to 15.1R7-S11; 18.3 versions prior to 18.3R3-S6; 18.4 versions prior to 18.4R3-S10; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R3-S4; 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R3-S2; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2.

EPSS: 0.007 (49.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N.

Affected products

Juniper Junos — versions 12.3, 15.1, 18.3
Juniper Networks Junos Os — versions 12.3, 15.1, 18.3

Weakness classification (CWE)

References

sirt@juniper.net (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2021-31386?: CVE-2021-31386 is a medium-severity vulnerability in Juniper Junos, classified under Channel Accessible by Non-Endpoint. CVSS score: 5.3/10. Published 2021-10-19.
How severe is CVE-2021-31386?: Medium severity. CVSS v3 base score is 5.3 out of 10.