CVE-2021-31367 json
Junos OS: PTX Series: An FPC heap memory leak will be triggered by certain Flowspec route operations which can lead to an FPC crash
published 2021-10-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18277
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 34%
- public exploits
- 0
- none known
Summary
A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on PTX Series allows an adjacent attacker to cause a Denial of Service (DoS) by sending genuine BGP flowspec packets which cause an FPC heap memory leak. Once having run out of memory the FPC will crash and restart along with a core dump. Continued receipted of these packets will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS All versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R3-S6; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos Evolved is not affected.
Patch / fix
- Juniper Networks Junos OS 18.4R3-S9, 19.1R3-S7, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R1-S4, 19.4R3-S6, 20.1R2-S2, 20.1R3, 20.2R3-S1, 20.3R3, 20.4R3, 21.1R2
- kb.juniper.net/JSA11229 advisory
Exploit prediction
0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 2.9 | AV:A/AC:M/Au:N/C:N/I:N/A:P |
Affected products
- Juniper Networks Junos OS
Classification
- Weakness
-
- CWE-401 Missing Release of Memory after Effective Lifetime
References
-
kb.juniper.net
/JSA11229
patch, vendor-advisory
Sources
- CVE List CVE-2021-31367
- NVD CVE-2021-31367
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