Stored cross-site scripting in Junos OS - CVE-2021-31355
Published: October 19, 2021
Vulnerability identifier: #VU57440
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2021-31355
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in the captive portal graphical user interface. A remote authenticated attacker can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Affected software
Junos OS
How to mitigate CVE-2021-31355
Install updates from vendor's website.
Junos OS - addressed in versions 12.3X48-D105, 15.1X49-D220, 18.3R3-S5, 18.4R3-S9, 19.1R3-S7, 19.2R3-S3, 19.3R3-S4, 19.4R3-S6, 20.1R3, 20.2R1-S1, 20.2R2, 20.3R2, 20.4R2, 21.1R2, 21.2R1