Vulnerability Monitor

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CVE-2021-0295


A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) of Juniper Networks Junos OS on the QFX10K Series switches allows an attacker to trigger a packet forwarding loop, leading to a partial Denial of Service (DoS). The issue is caused by DVMRP packets looping on a multi-homed Ethernet Segment Identifier (ESI) when VXLAN is configured. DVMRP packets received on a multi-homed ESI are sent to the peer, and then incorrectly forwarded out the same ESI, violating the split horizon rule. This issue only affects QFX10K Series switches, including the QFX10002, QFX10008, and QFX10016. Other products and platforms are unaffected by this vulnerability. This issue affects Juniper Networks Junos OS on QFX10K Series: 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 version 18.2R1 and later versions; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R2-S9, 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R1-S7, 19.2R3-S2; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R3-S3; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.1, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited integrity, and limited availability for affected systems. Impacting 5 products from juniper, from juniper, from juniper and 2 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

2021-07-15T20:15:11.353

Last Modified

2024-11-21T05:42:25.663

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.1 (MEDIUM)

CVSSv2 Vector

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

  • Access Vector: ADJACENT_NETWORK
  • Access Complexity: MEDIUM
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

5.5

Impact Score

2.9

Weaknesses
  • Type: Secondary
    CWE-697
  • Type: Primary
    CWE-697

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
Operating System juniper junos 17.3 Yes
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 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 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 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 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 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 Yes
Operating System juniper junos 18.1 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 18.2 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 18.2 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 18.2 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 18.2 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.3 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 Yes
Operating System juniper junos 18.4 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 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 Yes
Operating System juniper junos 19.1 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 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.2 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 Yes
Operating System juniper junos 19.3 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 19.4 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 19.4 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 20.1 Yes
Operating System juniper junos 20.1 Yes
Operating System juniper junos 20.1 Yes
Operating System juniper junos 20.1 Yes
Operating System juniper junos 20.1 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 20.2 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 20.2 Yes
Operating System juniper junos 20.3 Yes
Operating System juniper junos 20.3 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
Hardware juniper qfx10000 - No
Hardware juniper qfx10002 - No
Hardware juniper qfx10008 - No
Hardware juniper qfx10016 - 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.