CVE-2021-31373

A persistent Cross-Site Scripting (XSS) vulnerability in Juniper Networks Junos OS on SRX Series, J-Web interface may allow a remote authenticated user to inject persistent and malicious scripts. An attacker can exploit this vulnerability to steal sensitive data and credentials from a web administration session, or hijack another user's active session to perform administrative actions. This issue affects: Juniper Networks Junos OS on SRX Series: 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R2-S1, 20.3R3.

• CWE-20
• CWE-79
• CWE-79

• https://kb.juniper.net/JSA11238Vendor Advisory
• https://kb.juniper.net/JSA11238Vendor Advisory

Published

Oct 19, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-31368An Uncontrolled Resource Consumption vulnerability in the ke…7.5
• CVE-2021-31369On MX Series platforms with MS-MPC/MS-MIC, an Allocation of …5.3
• CVE-2021-3137XWiki 12.10.2 allows XSS via an SVG document to the upload f…5.4
• CVE-2021-31370An Incomplete List of Disallowed Inputs vulnerability in Pac…6.5
• CVE-2021-31371Juniper Networks Junos OS uses the 128.0.0.0/2 subnet for in…5.3
• CVE-2021-31372An Improper Input Validation vulnerability in J-Web of Junip…8.8
• CVE-2021-31374On Juniper Networks Junos OS and Junos OS Evolved devices pr…7.5
• CVE-2021-31375An Improper Input Validation vulnerability in routing proces…5.3
• CVE-2021-31376An Improper Input Validation vulnerability in Packet Forward…7.5
• CVE-2021-31377An Incorrect Permission Assignment for Critical Resource vul…5.5
• CVE-2021-31378In broadband environments, including but not limited to Enha…7.5
• CVE-2021-31379An Incorrect Behavior Order vulnerability in the MAP-E autom…7.5