Home/CVE/An Improper Check for Unusual or Exceptional Conditions vulnerability combined with Improper Handling of Exceptional Con
CVE

CVE-2021-31361

An Improper Check for Unusual or Exceptional Conditions vulnerability combined with Improper Handling of Exceptional Con

An Improper Check for Unusual or Exceptional Conditions vulnerability combined with Improper Handling of Exceptional Conditions in Juniper Networks Junos OS on QFX Series and PTX Series allows an unauthenticated network based attacker to cause increased FPC CPU utilization by sending specific IP packets which are being VXLAN encapsulated leading to a partial Denial of Service (DoS). Continued receipted of these specific traffic will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on QFX Series: All versions prior to 17.3R3-S11.

17.4 versions prior to 17.4R2-S13, 17.4R3-S4.

18.1 versions prior to 18.1R3-S12.

18.2 versions prior to 18.2R2-S8, 18.2R3-S7.

18.3 versions prior to 18.3R3-S4.

18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7.

19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4.

19.2 versions prior to 19.2R1-S6, 19.2R3-S2.

19.3 versions prior to 19.3R3-S1.

19.4 versions prior to 19.4R2-S3, 19.4R3-S1.

20.1 versions prior to 20.1R2, 20.1R3.

20.2 versions prior to 20.2R2, 20.2R3.

20.3 versions prior to 20.3R1-S1, 20.3R2. Juniper Networks Junos OS on PTX Series: All versions prior to 18.4R3-S9.

19.1 versions prior to 19.1R3-S6.

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-S5.

20.1 versions prior to 20.1R2-S2, 20.1R3.

20.2 versions prior to 20.2R3-S1.

20.3 versions prior to 20.3R2-S1, 20.3R3.

20.4 versions prior to 20.4R2-S1, 20.4R3.

21.1 versions prior to 21.1R1-S1, 21.1R2.

MEDIUM · CVSS 5.3 EPSS 0.00458
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0

Scoring & Timeline

5.3
MEDIUM · CVSS v3.1 · sirt@juniper.net
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 Oct 2021 · 07:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
Intelligence Graph · click any node to traverse
CVETechnique ActorTool Family
drag to reposition · click any node to traverse · button top-right enlarges
External lookups - second-class, for what we don’t hold ourselves
Vulnerabilities
CISA KEV catalog
CWE weaknesses
CAPEC attack patterns
Package vulnerabilities
Threat intelligence
Threat actors
Tools & malware
ATT&CK techniques
IOCs
Detection & defense
Sigma rules
YARA rules
Atomic Red Team tests
D3FEND countermeasures
Compliance
NIST 800-53
ISO 27001:2022
SOC 2 TSC
PCI-DSS v4.0
CIS Controls v8.1
About
All capabilities
Live statistics
Data sources
Privacy policy
Terms of service
threatengine.sh  ·  Open-source threat intelligence platform  ·  100+ authoritative sources  ·  Every fact traces to its origin