CVE-2021-1619

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 1.8%, top 24% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 9.8Exploit: None knownExposed: 0

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

A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected device Cause memory corruption that results in a denial of service (DoS) on an affected device This vulnerability is due to an uninitialized variable. An attacker could exploit this vulnerability by sending a series of NETCONF or RESTCONF requests to an affected device. A successful exploit could allow the attacker to use NETCONF or RESTCONF to install, manipulate, or delete the configuration of a network device or to corrupt memory on the device, resulting a DoS.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
60(Track)
EG Risk 60/100SSVC: Track

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
Severity98% × 45%
Exploitation2% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
76%
KEV
Not listed

Published

September 23, 2021

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated Jun 21, 2026
No patch confirmed yet.
generic

Cisco IOS XE Software NETCONF and RESTCONF Authentication Bypass Vulnerability

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aaa-Yx47ZT8Q

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× 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.

Showing the most recent 100 of 104 total refreshes for this CVE.

  1. 2026-07-26 14:52 UTCEPSS rescore
  2. 2026-07-25 14:15 UTCEPSS rescore
  3. 2026-07-24 14:15 UTCEPSS rescore
  4. 2026-07-23 14:15 UTCEPSS rescore
  5. 2026-07-23 01:56 UTCEG score recompute
  6. 2026-07-22 22:42 UTCEG score recompute▲ 0.70
  7. 2026-07-22 14:05 UTCEPSS rescore
  8. 2026-07-21 15:22 UTCEPSS rescore
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  10. 2026-07-20 17:04 UTCEPSS rescore
  11. 2026-07-19 14:28 UTCEPSS rescore
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  24. 2026-07-11 08:25 UTCEPSS rescore
  25. 2026-07-09 19:07 UTCEPSS rescore
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  1. 2026-07-08 15:12 UTCEPSS rescore
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  19. 2026-06-27 03:06 UTCEPSS rescore
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  21. 2026-06-25 13:48 UTCEPSS rescore
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  23. 2026-06-24 14:03 UTCEPSS rescore
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  25. 2026-06-23 21:31 UTCEPSS rescore
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  27. 2026-06-22 14:24 UTCEPSS rescore
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  29. 2026-06-21 14:54 UTCEPSS rescore
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  31. 2026-06-21 01:58 UTCEPSS rescore
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  35. 2026-06-18 17:51 UTCEPSS rescore
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  40. 2026-06-14 23:15 UTCEPSS rescore
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  42. 2026-06-12 23:10 UTCEPSS rescore
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  44. 2026-06-11 13:58 UTCEPSS rescore
  45. 2026-06-10 22:16 UTCEPSS rescore
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  47. 2026-06-10 13:20 UTCEPSS rescore
  48. 2026-06-08 14:15 UTCEPSS rescore
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  50. 2026-06-07 15:23 UTCEPSS rescore
  51. 2026-06-07 15:23 UTCEPSS rescore
  52. 2026-06-06 13:46 UTCEPSS rescore
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  60. 2026-06-04 13:10 UTCEPSS rescore
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  63. 2026-06-01 13:50 UTCEPSS rescore
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  69. 2026-05-29 13:42 UTCEPSS rescore
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  72. 2026-05-27 13:39 UTCEPSS rescore
  73. 2026-05-26 13:42 UTCEPSS rescore
  74. 2026-05-26 13:42 UTCEPSS rescore
  75. 2026-05-26 10:02 UTCEG score recompute

Frequently asked(5)

What is CVE-2021-1619?
CVE-2021-1619 is a critical vulnerability published on September 23, 2021. A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected…
When was CVE-2021-1619 disclosed?
CVE-2021-1619 was first published in the National Vulnerability Database on September 23, 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-2021-1619 actively exploited?
CVE-2021-1619 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 24.4% of all scored CVEs.
What is the CVSS score of CVE-2021-1619?
CVE-2021-1619 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2021-1619?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1619, 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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