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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
7.5HIGHmedium confidence
EG Risk
39
EG Risk 39/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation1% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.5%
EPSS %ILE
73rd
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

November 9, 2021

Last Modified

November 21, 2024

References (6)

Affected Packages

(10 across 4 ecosystems)
Debian:11(3)
PackageVulnerable rangeFix by version rangeDependents
cfrpki1.2.2-1, 1.3.0-1, 1.4.0-1
  • every version up to 1.4.2-1~deb11u1: fixed in 1.4.2-1~deb11u1
—
fort-validator1.5.0-1, 1.5.1-1, 1.5.2-1
  • every version up to 1.5.3-1~deb11u1: fixed in 1.5.3-1~deb11u1
—
rpki-client6.8p1-2 ... 9.8-1~bpo13+1 (56 versions)
  • every version on: no fix on record
—
Debian:12(3)
PackageVulnerable rangeFix by version rangeDependents
cfrpki—
  • every version up to 1.4.0-1: fixed in 1.4.0-1
—
fort-validator—
  • every version up to 1.5.3-1: fixed in 1.5.3-1
—
rpki-client—
  • every version up to 7.5-1: fixed in 7.5-1
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
fort-validator—
  • every version up to 1.5.3-1: fixed in 1.5.3-1
—
rpki-client—
  • every version up to 7.5-1: fixed in 7.5-1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
fort-validator—
  • every version up to 1.5.3-1: fixed in 1.5.3-1
—
rpki-client—
  • every version up to 7.5-1: fixed in 7.5-1
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 32× 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.

Showing the most recent 100 of 188 total refreshes for this CVE.

  1. 2026-10-10 19:56 UTCEPSS rescore
  2. 2026-10-09 20:04 UTCEPSS rescore
  3. 2026-10-08 16:40 UTCEPSS rescore
  4. 2026-10-07 23:45 UTCEPSS rescore
  5. 2026-10-06 15:14 UTCEPSS rescore
  6. 2026-10-05 17:40 UTCEPSS rescore
  7. 2026-10-04 23:19 UTCEPSS rescore
  8. 2026-10-03 14:22 UTCEPSS rescore
  9. 2026-10-02 16:23 UTCEPSS rescore
  10. 2026-10-01 19:46 UTCEPSS rescore
  11. 2026-09-30 15:42 UTCEG score recompute
  12. 2026-09-30 15:00 UTCEPSS rescore
  13. 2026-09-29 15:15 UTCEPSS rescore
  14. 2026-09-28 13:47 UTCEPSS rescore
  15. 2026-09-27 13:41 UTCEPSS rescore
  16. 2026-09-26 15:54 UTCEPSS rescore
  17. 2026-09-26 00:21 UTCEPSS rescore
  18. 2026-09-25 13:15 UTCOSV refresh
  19. 2026-09-24 14:00 UTCEPSS rescore
  20. 2026-09-24 14:00 UTCEPSS rescore
  21. 2026-09-23 13:44 UTCEPSS rescore
  22. 2026-09-22 14:44 UTCEPSS rescore
  23. 2026-09-21 20:28 UTCEPSS rescore
  24. 2026-09-19 15:38 UTCEPSS rescore
  25. 2026-09-18 19:23 UTCEPSS rescore
Show 75 more
  1. 2026-09-17 19:23 UTCEPSS rescore
  2. 2026-09-17 19:23 UTCEPSS rescore
  3. 2026-09-16 14:05 UTCEPSS rescore
  4. 2026-09-15 03:06 UTCEPSS rescore
  5. 2026-09-12 14:57 UTCEPSS rescore
  6. 2026-09-11 14:49 UTCEPSS rescore
  7. 2026-09-11 09:33 UTCEPSS rescore
  8. 2026-09-08 21:56 UTCEPSS rescore
  9. 2026-09-07 15:58 UTCEPSS rescore
  10. 2026-09-06 13:45 UTCEPSS rescore
  11. 2026-09-06 03:52 UTCOSV refresh
  12. 2026-09-05 15:25 UTCEPSS rescore
  13. 2026-09-04 13:57 UTCEPSS rescore
  14. 2026-09-04 05:03 UTCEPSS rescore
  15. 2026-09-02 14:09 UTCEPSS rescore
  16. 2026-09-01 13:50 UTCEPSS rescore
  17. 2026-09-01 03:33 UTCEPSS rescore
  18. 2026-08-30 19:14 UTCEPSS rescore
  19. 2026-08-30 19:14 UTCEPSS rescore
  20. 2026-08-30 01:19 UTCEPSS rescore
  21. 2026-08-28 21:37 UTCEPSS rescore
  22. 2026-08-27 14:22 UTCEPSS rescore
  23. 2026-08-26 14:43 UTCEPSS rescore
  24. 2026-08-25 13:46 UTCEPSS rescore
  25. 2026-08-24 14:13 UTCEPSS rescore
  26. 2026-08-23 00:16 UTCEPSS rescore
  27. 2026-08-21 23:46 UTCEPSS rescore
  28. 2026-08-20 22:52 UTCEPSS rescore
  29. 2026-08-20 22:52 UTCEPSS rescore
  30. 2026-08-19 17:01 UTCEPSS rescore
  31. 2026-08-19 15:02 UTCOSV refresh
  32. 2026-08-18 13:45 UTCEPSS rescore
  33. 2026-08-17 13:44 UTCEPSS rescore
  34. 2026-08-16 14:53 UTCEPSS rescore
  35. 2026-08-16 02:11 UTCEPSS rescore
  36. 2026-08-15 01:27 UTCEPSS rescore
  37. 2026-08-13 21:57 UTCEPSS rescore
  38. 2026-08-12 13:48 UTCEPSS rescore
  39. 2026-08-11 13:38 UTCEPSS rescore
  40. 2026-08-09 13:44 UTCEPSS rescore
  41. 2026-08-08 16:33 UTCEPSS rescore
  42. 2026-08-07 16:24 UTCEPSS rescore
  43. 2026-08-06 13:44 UTCEPSS rescore
  44. 2026-08-05 19:14 UTCEPSS rescore
  45. 2026-08-04 10:57 UTCOSV refresh
  46. 2026-08-04 10:34 UTCEPSS rescore
  47. 2026-08-03 10:33 UTCEPSS rescore
  48. 2026-08-02 02:24 UTCEPSS rescore
  49. 2026-08-01 04:13 UTCEPSS rescore
  50. 2026-07-30 16:25 UTCEPSS rescore
  51. 2026-07-30 01:28 UTCEPSS rescore
  52. 2026-07-28 15:33 UTCEPSS rescore
  53. 2026-07-26 14:52 UTCEPSS rescore
  54. 2026-07-26 14:52 UTCEPSS rescore
  55. 2026-07-25 14:15 UTCEPSS rescore
  56. 2026-07-24 14:15 UTCEPSS rescore
  57. 2026-07-23 14:16 UTCEPSS rescore
  58. 2026-07-23 02:05 UTCEG score recompute
  59. 2026-07-22 22:51 UTCEG score recompute
  60. 2026-07-22 14:06 UTCEPSS rescore
  61. 2026-07-21 15:22 UTCEPSS rescore
  62. 2026-07-21 15:22 UTCEPSS rescore
  63. 2026-07-20 17:05 UTCEPSS rescore
  64. 2026-07-19 14:29 UTCEPSS rescore
  65. 2026-07-19 02:27 UTCEPSS rescore
  66. 2026-07-18 10:02 UTCEPSS rescore
  67. 2026-07-18 10:02 UTCEPSS rescore
  68. 2026-07-18 07:59 UTCOSV refresh
  69. 2026-07-16 17:00 UTCEPSS rescore
  70. 2026-07-16 17:00 UTCEPSS rescore
  71. 2026-07-15 16:55 UTCEPSS rescore
  72. 2026-07-15 16:55 UTCEPSS rescore
  73. 2026-07-15 01:58 UTCEPSS rescore
  74. 2026-07-13 22:27 UTCEPSS rescore
  75. 2026-07-13 22:27 UTCEPSS rescore

Related CVEs(same product + 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 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 1.5% probability of exploitation in the next 30 days (73rd percentile of EPSS-scored CVEs).
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?
A fix for CVE-2021-43173 is available: update to the fixed version the vendor names in its advisory.

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