CVE-2021-43173

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

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

In NLnet Labs Routinator prior to 0.10.2, a validation run can be delayed significantly by an RRDP repository by not answering but slowly drip-feeding bytes to keep the connection alive. This can be used to effectively stall validation. While Routinator has a configurable time-out value for RRDP connections, this time-out was only applied to individual read or write operations rather than the complete request. Thus, if an RRDP repository sends a little bit of data before that time-out expired, it can continuously extend the time it takes for the request to finish. Since validation will only continue once the update of an RRDP repository has concluded, this delay will cause validation to stall, leading to Routinator continuing to serve the old data set or, if in the initial validation run directly after starting, never serve any data at all.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
70.0%
KEV
Not listed

Published

November 9, 2021

Last Modified

November 21, 2024

References (6)

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 49× 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. 2026-07-12 05:44 UTCEPSS rescore
  2. 2026-07-11 08:25 UTCEPSS rescore
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  17. 2026-06-30 23:20 UTCEPSS rescore
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  19. 2026-06-30 06:30 UTCOSV refresh
  20. 2026-06-28 14:05 UTCEPSS rescore
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  1. 2026-06-25 13:48 UTCEPSS rescore
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  4. 2026-06-23 21:31 UTCEPSS rescore
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  6. 2026-06-22 14:24 UTCEPSS rescore
  7. 2026-06-21 14:55 UTCEPSS rescore
  8. 2026-06-21 01:58 UTCEPSS rescore
  9. 2026-06-21 01:58 UTCEPSS rescore
  10. 2026-06-19 19:24 UTCEPSS rescore
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  12. 2026-06-18 17:51 UTCEPSS rescore
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  22. 2026-06-13 22:58 UTCEPSS rescore
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  24. 2026-06-12 23:10 UTCEPSS rescore
  25. 2026-06-12 17:10 UTCOSV refresh
  26. 2026-06-11 13:58 UTCEPSS rescore
  27. 2026-06-11 13:58 UTCEPSS rescore
  28. 2026-06-10 22:16 UTCEPSS rescore
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  30. 2026-06-10 13:20 UTCEPSS rescore
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  40. 2026-06-04 13:10 UTCEPSS rescore
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  42. 2026-06-02 20:11 UTCEPSS rescore
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  44. 2026-06-01 13:50 UTCEPSS rescore
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  46. 2026-05-31 22:29 UTCEPSS rescore
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  48. 2026-05-31 00:15 UTCEPSS rescore
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  50. 2026-05-29 13:42 UTCEPSS rescore
  51. 2026-05-28 13:43 UTCEPSS rescore
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  53. 2026-05-27 13:39 UTCEPSS rescore
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  55. 2026-05-26 13:42 UTCEPSS rescore
  56. 2026-05-26 13:42 UTCEPSS rescore
  57. 2026-05-26 07:48 UTCEG score recompute
  58. 2026-05-26 07:48 UTCGHSA enrichment
  59. 2026-05-26 07:17 UTCEPSS rescore
  60. 2026-05-26 07:17 UTCEPSS rescore
  61. 2026-05-26 07:17 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-43173?
CVE-2021-43173 is a high vulnerability published on November 9, 2021. In NLnet Labs Routinator prior to 0.10.2, a validation run can be delayed significantly by an RRDP repository by not answering but slowly drip-feeding bytes to keep the connection alive. This can be used to effectively stall validation. While Routinator has a configurable time-out value for RRDP…
When was CVE-2021-43173 disclosed?
CVE-2021-43173 was first published in the National Vulnerability Database on November 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-2021-43173 actively exploited?
CVE-2021-43173 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 70.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-43173?
CVE-2021-43173 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2021-43173?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-43173, 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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