Vulnerability identifier: #VU57440

Vulnerability risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-31355

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Juniper Junos OS
Operating systems & Components / Operating system

Vendor: Juniper Networks, Inc.

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 12.3x48 - 12.3X48-D101, 15.1X49 - 15.1X49-D211, 15.1X49-D210, 18.3R1 - 18.3R3-S4, 18.3R3-S1, 18.3R2-S3, 18.4R1 - 18.4R3-S8, 18.4R2-S3, 18.4R1-S5, 19.1R - 19.1R3-S6, 19.1R1-S4, 19.2R1 - 19.2R3-S2, 19.2R1-S4, 19.3R2 - 19.3R2-S7, 19.3R1 - 19.3R3-S3, 19.3R1-S1, 19.4R2 - 19.4R3-S5, 19.4R1 - 19.4R1-S4, 20.1R1 - 20.1R2-S2, 20.2R1, 20.3R1 - 20.3R1-S2, 20.4R1 - 20.4R1-S1, 21.1R1 - 21.1R1-S1

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External links
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA11220&cat=SIRT_1&actp=LIST

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.