CVE-2021-31355 is a persistent cross-site scripting (XSS) vulnerability in the captive portal GUI of Juniper Networks Junos OS, affecting numerous versions across multiple release trains. An authenticated attacker can inject malicious web script or HTML to steal sensitive data or credentials from an administrative session, potentially leading to unauthorized administrative actions. Rated as Medium severity (CVSS 5.4), this vulnerability requires authenticated access and user interaction (UI:R), but its impact includes low confidentiality and integrity. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 12.3X48, < 12.3X48-D105CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 15.1X49, < 15.1X49-D220CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 18.3, < 18.3R3-S5CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 18.4, < 18.4R3-S9CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | ||
>= 19.1, < 19.1R3-S7CPE match | cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
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