CVE-2021-31377 json
Junos OS: A local authenticated attacker can cause RPD to core
published 2021-10-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18287
- cvss
- 5.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
Summary
An Incorrect Permission Assignment for Critical Resource vulnerability of a certain file in the filesystem of Junos OS allows a local authenticated attacker to cause routing process daemon (RPD) to crash and restart, causing a Denial of Service (DoS). Repeated actions by the attacker will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13, 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S8, 18.4R3-S7; 19.1 versions prior to 19.1R2-S3, 19.1R3-S5; 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S2; 19.4 versions prior to 19.4R1-S4, 19.4R2-S4, 19.4R3-S2; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R1-S1, 20.4R2.
Patch / fix
- Juniper Networks Junos OS 15.1R7-S9, 17.3R3-S12, 17.4R2-S13, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R2-S8, 18.4R3-S7, 19.1R2-S3, 19.1R3-S5, 19.2R3-S2, 19.3R2-S6, 19.3R3-S2, 19.4R1-S4, 19.4R2-S4, 19.4R3-S2, 20.1R2-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R3, 20.4R1-S1, 20.4R2
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 2.1 | AV:L/AC:L/Au:N/C:N/I:N/A:P |
Affected products
- Juniper Networks Junos OS
Classification
- Weakness
-
- CWE-732 Incorrect Permission Assignment for Critical Resource
References
-
kb.juniper.net
/JSA11242
vendor-advisory
Sources
- CVE List CVE-2021-31377
- NVD CVE-2021-31377
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