CVE-2021-34713

HIGHNVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 71% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.4
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.4Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.4
EG Score
7.4(medium)
EG Risk
—
EPSS
28.5%
KEV
Not listed

Published

September 9, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 22:48 UTCEG score recompute
  2. 2026-07-22 14:06 UTCEPSS rescore
  3. 2026-07-22 14:06 UTCEPSS rescore
  4. 2026-07-21 15:22 UTCEPSS rescore
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  6. 2026-07-20 17:05 UTCEPSS rescore
  7. 2026-07-19 14:29 UTCEPSS rescore
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  9. 2026-07-19 02:27 UTCEPSS rescore
  10. 2026-07-18 10:02 UTCEPSS rescore
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  12. 2026-07-16 17:00 UTCEPSS rescore
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  14. 2026-07-15 16:55 UTCEPSS rescore
  15. 2026-07-15 01:58 UTCEPSS rescore
  16. 2026-07-13 22:27 UTCEPSS rescore
  17. 2026-07-13 06:10 UTCEPSS rescore
  18. 2026-07-12 05:44 UTCEPSS rescore
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  20. 2026-07-11 08:25 UTCEPSS rescore
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  22. 2026-07-09 19:07 UTCEPSS rescore
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  1. 2026-07-05 02:28 UTCEPSS rescore
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  3. 2026-07-04 06:29 UTCEPSS rescore
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  5. 2026-07-01 15:04 UTCEPSS rescore
  6. 2026-06-30 23:20 UTCEPSS rescore
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  8. 2026-06-29 14:04 UTCEPSS rescore
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  17. 2026-06-23 21:31 UTCEPSS rescore
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  19. 2026-06-22 14:24 UTCEPSS rescore
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  21. 2026-06-21 14:55 UTCEPSS rescore
  22. 2026-06-21 01:58 UTCEPSS rescore
  23. 2026-06-21 01:58 UTCEPSS rescore
  24. 2026-06-19 19:24 UTCEPSS rescore
  25. 2026-06-19 19:24 UTCEPSS rescore
  26. 2026-06-18 17:51 UTCEPSS rescore
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  28. 2026-06-17 17:51 UTCEPSS rescore
  29. 2026-06-16 17:51 UTCEPSS rescore
  30. 2026-06-16 17:51 UTCEPSS rescore
  31. 2026-06-15 17:46 UTCEPSS rescore
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  35. 2026-06-12 23:10 UTCEPSS rescore
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  37. 2026-06-11 13:58 UTCEPSS rescore
  38. 2026-06-10 22:16 UTCEPSS rescore
  39. 2026-06-10 13:20 UTCEPSS rescore
  40. 2026-06-08 14:15 UTCEPSS rescore
  41. 2026-06-08 14:15 UTCEPSS rescore
  42. 2026-06-07 15:23 UTCEPSS rescore
  43. 2026-06-07 15:23 UTCEPSS rescore
  44. 2026-06-06 13:46 UTCEPSS rescore
  45. 2026-06-06 13:46 UTCEPSS rescore
  46. 2026-06-06 13:46 UTCEPSS rescore
  47. 2026-06-05 22:45 UTCEPSS rescore
  48. 2026-06-05 06:09 UTCEPSS rescore
  49. 2026-06-05 06:09 UTCEPSS rescore
  50. 2026-06-04 13:10 UTCEPSS rescore
  51. 2026-06-04 13:10 UTCEPSS rescore
  52. 2026-06-02 20:11 UTCEPSS rescore
  53. 2026-06-02 20:11 UTCEPSS rescore
  54. 2026-06-01 13:50 UTCEPSS rescore
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  56. 2026-05-31 22:29 UTCEPSS rescore
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  58. 2026-05-31 00:15 UTCEPSS rescore
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  60. 2026-05-29 13:42 UTCEPSS rescore
  61. 2026-05-29 13:42 UTCEPSS rescore
  62. 2026-05-28 13:43 UTCEPSS rescore
  63. 2026-05-28 13:43 UTCEPSS rescore
  64. 2026-05-27 13:39 UTCEPSS rescore
  65. 2026-05-27 13:39 UTCEPSS rescore
  66. 2026-05-27 13:39 UTCEPSS rescore
  67. 2026-05-26 13:42 UTCEPSS rescore
  68. 2026-05-26 10:42 UTCEG score recompute
  69. 2026-05-26 10:42 UTCGHSA enrichment
  70. 2026-05-26 07:17 UTCEPSS rescore
  71. 2026-05-26 07:17 UTCEPSS rescore
  72. 2026-05-26 07:17 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-34713?
CVE-2021-34713 is a high vulnerability published on September 9, 2021. 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…
When was CVE-2021-34713 disclosed?
CVE-2021-34713 was first published in the National Vulnerability Database on September 9, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-34713 actively exploited?
CVE-2021-34713 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 28.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-34713?
CVE-2021-34713 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2021-34713?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-34713, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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