Vulnerability Monitor

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CVE-2021-34713


A vulnerability in the Layer 2 punt code of Cisco IOS XR Software running on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, adjacent attacker to cause the affected line card to reboot. This vulnerability is due to incorrect handling of specific Ethernet frames that cause a spin loop that can make the network processors unresponsive. An attacker could exploit this vulnerability by sending specific types of Ethernet frames on the segment where the affected line cards are attached. A successful exploit could allow the attacker to cause the affected line card to reboot.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.4, indicating it requires adjacent network access 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 14 products from cisco, from cisco, from cisco and 11 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

2021-09-09T05:15:10.810

Last Modified

2024-11-21T06:11:01.577

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.4 (HIGH)

CVSSv2 Vector

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

  • Access Vector: ADJACENT_NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: COMPLETE
Exploitability Score

6.5

Impact Score

6.9

Weaknesses
  • Type: Secondary
    CWE-399
  • Type: Primary
    NVD-CWE-Other

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Operating System cisco ios_xr < 6.6.3 Yes
Operating System cisco ios_xr < 6.7.1 Yes
Operating System cisco ios_xr < 7.0.2 Yes
Operating System cisco ios_xr < 7.1.1 Yes
Hardware cisco asr_9000 - No
Hardware cisco asr_9000v-v2 - No
Hardware cisco asr_9001 - No
Hardware cisco asr_9006 - No
Hardware cisco asr_9010 - No
Hardware cisco asr_9901 - No
Hardware cisco asr_9902 - No
Hardware cisco asr_9903 - No
Hardware cisco asr_9904 - No
Hardware cisco asr_9906 - No
Hardware cisco asr_9910 - No
Hardware cisco asr_9912 - No
Hardware cisco asr_9922 - 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 cisco'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.