Vulnerability Monitor

The vendors, products, and vulnerabilities you care about

CVE-2021-31351


An Improper Check for Unusual or Exceptional Conditions in packet processing on the MS-MPC/MS-MIC utilized by Juniper Networks Junos OS allows a malicious attacker to send a specific packet, triggering the MS-MPC/MS-MIC to reset, causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects specific versions of Juniper Networks Junos OS on MX Series: 17.3R3-S11; 17.4R2-S13; 17.4R3 prior to 17.4R3-S5; 18.1R3-S12; 18.2R2-S8, 18.2R3-S7, 18.2R3-S8; 18.3R3-S4; 18.4R3-S7; 19.1R3-S4, 19.1R3-S5; 19.2R1-S6; 19.3R3-S2; 19.4R2-S4, 19.4R2-S5; 19.4R3-S2; 20.1R2-S1; 20.2R2-S2, 20.2R2-S3, 20.2R3; 20.3R2, 20.3R2-S1; 20.4R1, 20.4R1-S1, 20.4R2; 21.1R1; This issue does not affect any version of Juniper Networks Junos OS prior to 15.1X49-D240;


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 18 products from juniper, from juniper, from juniper and 15 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-10-19T19:15:08.597

Last Modified

2024-11-21T06:05:28.723

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.5 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

10.0

Impact Score

2.9

Weaknesses
  • Type: Secondary
    CWE-754
  • Type: Primary
    CWE-754

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 17.4 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.2 Yes
Operating System juniper junos 18.2 Yes
Operating System juniper junos 18.2 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.4 Yes
Operating System juniper junos 19.4 Yes
Operating System juniper junos 19.4 Yes
Operating System juniper junos 20.1 Yes
Operating System juniper junos 20.2 Yes
Operating System juniper junos 20.2 Yes
Operating System juniper junos 20.2 Yes
Operating System juniper junos 20.3 Yes
Operating System juniper junos 20.3 Yes
Operating System juniper junos 20.4 Yes
Operating System juniper junos 20.4 Yes
Operating System juniper junos 20.4 Yes
Operating System juniper junos 21.1 Yes
Hardware juniper mx10 - No
Hardware juniper mx10000 - No
Hardware juniper mx10003 - No
Hardware juniper mx10008 - No
Hardware juniper mx10016 - No
Hardware juniper mx104 - No
Hardware juniper mx150 - No
Hardware juniper mx2008 - No
Hardware juniper mx2010 - No
Hardware juniper mx2020 - No
Hardware juniper mx204 - No
Hardware juniper mx240 - No
Hardware juniper mx40 - No
Hardware juniper mx480 - No
Hardware juniper mx5 - No
Hardware juniper mx80 - No
Hardware juniper mx960 - No

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.