CVE-2021-31386: Junos OS: When using J-Web with HTTP an attacker may retrieve encryption keys via Person-in-the-Middle attacks.

Published Oct 19, 2021

Updated

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.

Affected Software

227 affected components

Juniper Junos=12.3

Juniper Junos=12.3-r1

Juniper Junos=12.3-r10

Juniper Junos=12.3-r10-s1

Juniper Junos=12.3-r10-s2

Juniper Junos=12.3-r11

Juniper Junos=12.3-r12

Juniper Junos=12.3-r12-s1

Juniper Junos=12.3-r12-s10

Juniper Junos=12.3-r12-s11

Juniper Junos=12.3-r12-s12

Juniper Junos=12.3-r12-s13

Juniper Junos=12.3-r12-s14

Juniper Junos=12.3-r12-s15

Juniper Junos=12.3-r12-s16

Juniper Junos=12.3-r12-s17

Juniper Junos=12.3-r12-s18

Juniper Junos=12.3-r12-s19

Juniper Junos=12.3-r12-s3

Juniper Junos=12.3-r12-s4

Juniper Junos=12.3-r12-s6

Juniper Junos=12.3-r12-s8

Juniper Junos=12.3-r2

Juniper Junos=12.3-r3

Juniper Junos=12.3-r4

Juniper Junos=12.3-r5

Juniper Junos=12.3-r6

Juniper Junos=12.3-r7

Juniper Junos=12.3-r8

Juniper Junos=12.3-r9

Juniper Junos=15.1

Juniper Junos=15.1-a1

Juniper Junos=15.1-f

Juniper Junos=15.1-f1

Juniper Junos=15.1-f2

Juniper Junos=15.1-f2-s1

Juniper Junos=15.1-f2-s2

Juniper Junos=15.1-f2-s3

Juniper Junos=15.1-f2-s4

Juniper Junos=15.1-f3

Juniper Junos=15.1-f4

Juniper Junos=15.1-f5

Juniper Junos=15.1-f5-s7

Juniper Junos=15.1-f6

Juniper Junos=15.1-f6-s1

Juniper Junos=15.1-f6-s10

Juniper Junos=15.1-f6-s12

Juniper Junos=15.1-f6-s2

Juniper Junos=15.1-f6-s3

Juniper Junos=15.1-f6-s4

Juniper Junos=15.1-f6-s5

Juniper Junos=15.1-f6-s6

Juniper Junos=15.1-f6-s7

Juniper Junos=15.1-f6-s8

Juniper Junos=15.1-f6-s9

Juniper Junos=15.1-f7

Juniper Junos=15.1-r

Juniper Junos=15.1-r1

Juniper Junos=15.1-r2

Juniper Junos=15.1-r3

Juniper Junos=15.1-r4

Juniper Junos=15.1-r4-s7

Juniper Junos=15.1-r4-s8

Juniper Junos=15.1-r4-s9

Juniper Junos=15.1-r5

Juniper Junos=15.1-r5-s1

Juniper Junos=15.1-r5-s3

Juniper Junos=15.1-r5-s5

Juniper Junos=15.1-r5-s6

Juniper Junos=15.1-r6

Juniper Junos=15.1-r6-s1

Juniper Junos=15.1-r6-s2

Juniper Junos=15.1-r6-s3

Juniper Junos=15.1-r6-s4

Juniper Junos=15.1-r6-s6

Juniper Junos=15.1-r7

Juniper Junos=15.1-r7-s1

Juniper Junos=15.1-r7-s10

Juniper Junos=15.1-r7-s2

Juniper Junos=15.1-r7-s3

Juniper Junos=15.1-r7-s4

Juniper Junos=15.1-r7-s5

Juniper Junos=15.1-r7-s6

Juniper Junos=15.1-r7-s7

Juniper Junos=15.1-r7-s8

Juniper Junos=15.1-r7-s9

Juniper Junos=18.3

Juniper Junos=18.3-r1

Juniper Junos=18.3-r1-s1

Juniper Junos=18.3-r1-s2

Juniper Junos=18.3-r1-s3

Juniper Junos=18.3-r1-s4

Juniper Junos=18.3-r1-s5

Juniper Junos=18.3-r1-s6

Juniper Junos=18.3-r2

Juniper Junos=18.3-r2-s1

Juniper Junos=18.3-r2-s2

Juniper Junos=18.3-r2-s3

Juniper Junos=18.3-r2-s4

Juniper Junos=18.3-r3

Juniper Junos=18.3-r3-s1

Juniper Junos=18.3-r3-s2

Juniper Junos=18.3-r3-s3

Juniper Junos=18.3-r3-s4

Juniper Junos=18.3-r3-s5

Juniper Junos=18.4

Juniper Junos=18.4-r1

Juniper Junos=18.4-r1-s1

Juniper Junos=18.4-r1-s2

Juniper Junos=18.4-r1-s3

Juniper Junos=18.4-r1-s4

Juniper Junos=18.4-r1-s5

Juniper Junos=18.4-r1-s6

Juniper Junos=18.4-r1-s7

Juniper Junos=18.4-r2

Juniper Junos=18.4-r2-s1

Juniper Junos=18.4-r2-s2

Juniper Junos=18.4-r2-s3

Juniper Junos=18.4-r2-s4

Juniper Junos=18.4-r2-s5

Juniper Junos=18.4-r2-s6

Juniper Junos=18.4-r2-s7

Juniper Junos=18.4-r2-s8

Juniper Junos=18.4-r3

Juniper Junos=18.4-r3-s1

Juniper Junos=18.4-r3-s2

Juniper Junos=18.4-r3-s3

Juniper Junos=18.4-r3-s4

Juniper Junos=18.4-r3-s5

Juniper Junos=18.4-r3-s6

Juniper Junos=18.4-r3-s7

Juniper Junos=18.4-r3-s8

Juniper Junos=18.4-r3-s9

Juniper Junos=19.1

Juniper Junos=19.1-r1

Juniper Junos=19.1-r1-s1

Juniper Junos=19.1-r1-s2

Juniper Junos=19.1-r1-s3

Juniper Junos=19.1-r1-s4

Juniper Junos=19.1-r1-s5

Juniper Junos=19.1-r1-s6

Juniper Junos=19.1-r2

Juniper Junos=19.1-r2-s1

Juniper Junos=19.1-r2-s2

Juniper Junos=19.1-r3

Juniper Junos=19.1-r3-s1

Juniper Junos=19.1-r3-s2

Juniper Junos=19.1-r3-s3

Juniper Junos=19.1-r3-s4

Juniper Junos=19.1-r3-s5

Juniper Junos=19.1-r3-s6

Juniper Junos=19.2

Juniper Junos=19.2-r1

Juniper Junos=19.2-r1-s1

Juniper Junos=19.2-r1-s2

Juniper Junos=19.2-r1-s3

Juniper Junos=19.2-r1-s4

Juniper Junos=19.2-r1-s5

Juniper Junos=19.2-r1-s6

Juniper Junos=19.2-r2

Juniper Junos=19.2-r2-s1

Juniper Junos=19.2-r3

Juniper Junos=19.2-r3-s1

Juniper Junos=19.2-r3-s2

Juniper Junos=19.2-r3-s3

Juniper Junos=19.3

Juniper Junos=19.3-r1

Juniper Junos=19.3-r1-s1

Juniper Junos=19.3-r2

Juniper Junos=19.3-r2-s1

Juniper Junos=19.3-r2-s2

Juniper Junos=19.3-r2-s3

Juniper Junos=19.3-r2-s4

Juniper Junos=19.3-r2-s5

Juniper Junos=19.3-r3

Juniper Junos=19.3-r3-s1

Juniper Junos=19.3-r3-s2

Juniper Junos=19.3-r3-s3

Juniper Junos=19.4-r1

Juniper Junos=19.4-r1-s1

Juniper Junos=19.4-r1-s2

Juniper Junos=19.4-r1-s3

Juniper Junos=19.4-r2

Juniper Junos=19.4-r2-s1

Juniper Junos=19.4-r2-s2

Juniper Junos=19.4-r2-s3

Juniper Junos=19.4-r2-s4

Juniper Junos=19.4-r3

Juniper Junos=19.4-r3-s1

Juniper Junos=19.4-r3-s2

Juniper Junos=19.4-r3-s3

Juniper Junos=19.4-r3-s4

Juniper Junos=19.4-r3-s5

Juniper Junos=20.1-r1

Juniper Junos=20.1-r1-s1

Juniper Junos=20.1-r1-s2

Juniper Junos=20.1-r1-s3

Juniper Junos=20.1-r1-s4

Juniper Junos=20.1-r2

Juniper Junos=20.1-r2-s1

Juniper Junos=20.1-r3

Juniper Junos=20.1-r3-s1

Juniper Junos=20.2-r1

Juniper Junos=20.2-r1-s1

Juniper Junos=20.2-r1-s2

Juniper Junos=20.2-r1-s3

Juniper Junos=20.2-r2

Juniper Junos=20.2-r2-s1

Juniper Junos=20.2-r2-s2

Juniper Junos=20.2-r2-s3

Juniper Junos=20.2-r3

Juniper Junos=20.2-r3-s1

Juniper Junos=20.2-r3-s2

Juniper Junos=20.3-r1

Juniper Junos=20.3-r1-s1

Juniper Junos=20.3-r2

Juniper Junos=20.3-r2-s1

Juniper Junos=20.3-r3

Juniper Junos=20.4-r1

Juniper Junos=20.4-r1-s1

Juniper Junos=20.4-r2

Juniper Junos=20.4-r2-s1

Juniper Junos=21.1-r1

Juniper Junos=21.1-r1-s1

Juniper Junos=21.1-r2

Juniper Junos=21.2-r1

Juniper Junos=21.2-r1-s1

Remediation

Information

The following software releases have been updated to resolve this specific issue: 12.3R12-S20, 15.1R7-S11, 18.3R3-S6, 18.4R3-S10, 19.1R3-S7, 19.2R3-S4, 19.3R3-S4, 19.4R3-S6, 20.1R3-S2, 20.2R3-S3, 20.3R3-S1, 20.4R3, 21.1R3, 21.2R2, 21.3R1, and all subsequent releases. Note: Use of HTTP must also be discontinued.

Event History

Oct 19, 2021

CVE Published

via MITRE·06:17 PM

Data Sourced

via MITRE·06:17 PM

RemedyDescriptionSeverityWeakness

Frequently Asked Questions

What is the severity of CVE-2021-31386?

CVE-2021-31386 has been assigned a medium severity rating, indicating potential risk to security if exploited.

How do I fix CVE-2021-31386?

To fix CVE-2021-31386, users should upgrade to Junos OS version 12.3R12 or later.

Which versions of Junos OS are affected by CVE-2021-31386?

CVE-2021-31386 affects Junos OS versions 12.3 before 12.3R12, as well as versions 15.1, 18.3, 18.4, 19.1, 19.2, 19.3, and 20.x with specific versions listed.

What kind of attack can CVE-2021-31386 facilitate?

CVE-2021-31386 can facilitate Person-in-the-Middle (PitM) attacks due to a failure in the protection mechanism of the J-Web HTTP service.

Is CVE-2021-31386 exploitable by authenticated users?

No, CVE-2021-31386 is exploitable by remote unauthenticated attackers.