CVE-2021-0275 json
Junos OS: J-Web: Cross-site scripting attack allows an attacker to gain control of another users session.
published 2021-04-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-2894
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 67%
- public exploits
- 0
- none known
Summary
A Cross-site Scripting (XSS) vulnerability in J-Web on Juniper Networks Junos OS allows an attacker to target another user's session thereby gaining access to the users session. The other user session must be active for the attack to succeed. Once successful, the attacker has the same privileges as the user. If the user has root privileges, the attacker may be able to gain full control of the device. This issue affects: Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S15 on EX Series; 12.3X48 versions prior to 12.3X48-D95 on SRX Series; 15.1 versions prior to 15.1R7-S6 on EX Series; 15.1X49 versions prior to 15.1X49-D200 on SRX Series; 16.1 versions prior to 16.1R7-S7; 16.2 versions prior to 16.2R2-S11, 16.2R3; 17.1 versions prior to 17.1R2-S11, 17.1R3-S2; 17.2 versions prior to 17.2R3-S3; 17.3 versions prior to 17.3R2-S5, 17.3R3-S7; 17.4 versions prior to 17.4R2-S9, 17.4R3; 18.1 versions prior to 18.1R3-S9; 18.2 versions prior to 18.2R2-S7, 18.2R3-S3; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3-S1; 18.4 versions prior to 18.4R1-S6, 18.4R2-S4, 18.4R3; 19.1 versions prior to 19.1R2-S1, 19.1R3; 19.2 versions prior to 19.2R1-S3, 19.2R2; 19.3 versions prior to 19.3R2.
Patch / fix
- Juniper Networks Junos OS 12.3R12-S15, 12.3X48-D95, 15.1R7-S6, 15.1X49-D200, 16.1R7-S7, 16.2R2-S11, 16.2R3, 17.1R2-S11, 17.1R3-S2, 17.2R3-S3, 17.3R2-S5, 17.3R3-S7, 17.4R2-S9, 17.4R3, 18.1R3-S9, 18.2R2-S7, 18.2R3-S3, 18.3R1-S7, 18.3R2-S3, 18.3R3-S1, 18.4R1-S6, 18.4R2-S4, 18.4R3, 19.1R2-S1, 19.1R3, 19.2R1-S3, 19.2R2, 19.3R2
Exploit prediction
1.17% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 9.3 | AV:N/AC:M/Au:N/C:C/I:C/A:C |
Affected products
- Juniper Networks Junos OS
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
kb.juniper.net
/JSA11166
vendor-advisory
Sources
- CVE List CVE-2021-0275
- NVD CVE-2021-0275
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