CVE-2021-27561

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.8EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 83%CVSS: 9.8Exploit: cisa kev · ssvc active · epss top5pct · epss high · public exploitExposed: 0

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

Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS PROB
83%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

October 15, 2021

Last Modified

November 10, 2025

Advisory Details (2)

Auto-updated Sep 17, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27561
generic

SSD Advisory – Yealink DM Pre Auth 'root' level RCE - SSD Secure Disclosure

https://ssd-disclosure.com/?p=4688

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 48× in last 7d / 211× 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 755 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2021/CVE-2021-27561.yaml
    First seen Jan 1, 2021

    YeaLink DM 3.6.0.20 - Remote Command Injection

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-27561?
CVE-2021-27561 is a critical vulnerability published on October 15, 2021. Yealink Device Management (DM) 3.6.0.20 allows command injection as root via the /sm/api/v1/firewall/zone/services URI, without authentication.
When was CVE-2021-27561 disclosed?
CVE-2021-27561 was first published in the National Vulnerability Database on October 15, 2021, with the most recent update on November 10, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-27561 actively exploited?
Yes. CISA added CVE-2021-27561 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Yealink Device Management. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-27561?
CVE-2021-27561 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2021-27561?
CVE-2021-27561 affects Yealink Device Management. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-27561?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-27561, 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.

Dependency Blast Radius

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