CVE-2021-31372 json
Junos OS: J-Web allows a locally authenticated attacker to escalate their privileges to root.
published 2021-10-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18282
- 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 69%
- public exploits
- 0
- none known
Summary
An Improper Input Validation vulnerability in J-Web of Juniper Networks Junos OS allows a locally authenticated J-Web attacker to escalate their privileges to root over the target device. This issue affects: Juniper Networks Junos OS All versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2, 21.1R3; 21.2 versions prior to 21.2R1-S1, 21.2R2;
Patch / fix
- Juniper Networks Junos OS 18.3R3-S5, 18.4R3-S9, 19.1R3-S6, 19.2R3-S3, 19.3R3-S3, 19.4R3-S5, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 20.4R3, 21.1R2, 21.1R3, 21.2R1-S1, 21.2R2
Exploit prediction
1.23% chance of exploitation in the next 30 days, higher than 69% 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:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 9.0 | AV:N/AC:L/Au:S/C:C/I:C/A:C |
Affected products
- Juniper Networks Junos OS
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
kb.juniper.net
/JSA11237
vendor-advisory
Sources
- CVE List CVE-2021-31372
- NVD CVE-2021-31372
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