CVE-2021-31386

MediumCVSS 5.9/10Last modified Jun 17, 2026

Description

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.

Metrics

CVSS 3.1 5.9/10CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Weakness enumeration

CWE-300 CWE-311 CWE-325 CWE-693

Affected software

No affected versions have been published.

Timeline

Published: Oct 19, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-31398.1In Open-iSCSI tcmu-runner 1.3.x, 1.4.x, and 1.5.x through 1.5.2, xcopy_locate_udev in tcmur_cmd_handler.c lacks a check for transport-layer CVE-2021-313995.9On 2N Access Unit 2.0 2.31.0.40.5 devices, an attacker can pose as the web relay for a man-in-the-middle attack.CVE-2021-314007.5An issue was discovered in tcp_pulloutofband() in tcp_in.c in HCC embedded InterNiche 4.0.1. The TCP out-of-band urgent-data processing func CVE-2021-314017.5An issue was discovered in tcp_rcv() in nptcp.c in HCC embedded InterNiche 4.0.1. The TCP header processing code doesn't sanitize the value CVE-2021-314027.5The dio package 4.0.0 for Dart allows CRLF injection if the attacker controls the HTTP method string, a different vulnerability than CVE-202 CVE-2021-314032.5Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:vaadin-server versions 7.0.0 through 7.7.23 (Vaadin 7.0.0 CVE-2021-314042.5Non-constant-time comparison of CSRF tokens in UIDL request handler in com.vaadin:flow-server versions 1.0.0 through 1.0.13 (Vaadin 10.0.0 t CVE-2021-314057.5Unsafe validation RegEx in EmailField component in com.vaadin:vaadin-text-field-flow versions 2.0.4 through 2.3.2 (Vaadin 14.0.6 through 14.CVE-2021-314062.5Non-constant-time comparison of CSRF tokens in endpoint request handler in com.vaadin:flow-server versions 3.0.0 through 5.0.3 (Vaadin 15.0.CVE-2021-314077.5Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through 14.4.9), and 6.0.0 through 6 CVE-2021-314087.1Authentication.logout() helper in com.vaadin:flow-client versions 5.0.0 prior to 6.0.0 (Vaadin 18), and 6.0.0 through 6.0.4 (Vaadin 19.0.0 t CVE-2021-314097.5Unsafe validation RegEx in EmailValidator component in com.vaadin:vaadin-compatibility-server versions 8.0.0 through 8.12.4 (Vaadin versions