CVE-2018-4012

CRITICALNVD 9.09.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.0 under NVD CVSS v3. EPSS exploit probability: 2.5% (84th percentile of EPSS-scored CVEs). GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
9.0EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2.5%CVSS: 9.0Exploit: None knownExposed services: Not assessed

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

An exploitable buffer overflow vulnerability exists in the HTTP header-parsing function of the Webroot BrightCloud SDK. The function bc_http_read_header incorrectly handles overlong headers, leading to arbitrary code execution. An unauthenticated attacker could impersonate a remote BrightCloud server to trigger this vulnerability.

CVSS v3
9.0
EG Score
9.0CRITICALmedium confidence
EG Risk
46
EG Risk 46/100CISA 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
Severity90% × 45%
Exploitation3% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
2.5%
EPSS %ILE
84th
KEV
Not listed

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

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 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

January 3, 2019

Last Modified

November 21, 2024

Advisory Details (1)

Auto-updated Jul 26, 2026
🔬 Proof of concept available. No fix on record yet.
generic🟡 PoC Available

TALOS-2018-0683 || Cisco Talos Intelligence Group - Comprehensive Threat Intelligence

https://www.talosintelligence.com/vulnerability_reports/TALOS-2018-0683

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 20× 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 151 total refreshes for this CVE.

  1. 2026-10-05 17:39 UTCEPSS rescore
  2. 2026-10-04 23:18 UTCEPSS rescore
  3. 2026-10-03 14:21 UTCEPSS rescore
  4. 2026-10-01 19:44 UTCEPSS rescore
  5. 2026-09-30 14:59 UTCEPSS rescore
  6. 2026-09-30 10:01 UTCEG score recompute
  7. 2026-09-28 13:45 UTCEPSS rescore
  8. 2026-09-27 13:40 UTCEPSS rescore
  9. 2026-09-26 15:53 UTCEPSS rescore
  10. 2026-09-20 20:10 UTCEPSS rescore
  11. 2026-09-19 15:36 UTCEPSS rescore
  12. 2026-09-18 19:22 UTCEPSS rescore
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  16. 2026-09-12 14:56 UTCEPSS rescore
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  18. 2026-09-11 09:32 UTCEPSS rescore
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  20. 2026-09-06 13:43 UTCEPSS rescore
  21. 2026-09-05 15:24 UTCEPSS rescore
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  24. 2026-09-02 14:07 UTCEPSS rescore
  25. 2026-09-01 13:49 UTCEPSS rescore
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  1. 2026-09-01 03:32 UTCEPSS rescore
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  3. 2026-08-27 14:21 UTCEPSS rescore
  4. 2026-08-26 14:42 UTCEPSS rescore
  5. 2026-08-25 13:44 UTCEPSS rescore
  6. 2026-08-21 23:45 UTCEPSS rescore
  7. 2026-08-20 22:51 UTCEPSS rescore
  8. 2026-08-19 17:00 UTCEPSS rescore
  9. 2026-08-18 13:44 UTCEPSS rescore
  10. 2026-08-17 13:43 UTCEPSS rescore
  11. 2026-08-16 14:51 UTCEPSS rescore
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  14. 2026-08-13 21:56 UTCEPSS rescore
  15. 2026-08-12 13:46 UTCEPSS rescore
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  17. 2026-08-07 16:23 UTCEPSS rescore
  18. 2026-08-06 13:42 UTCEPSS rescore
  19. 2026-08-05 19:13 UTCEPSS rescore
  20. 2026-08-04 15:05 UTCEPSS rescore
  21. 2026-08-02 02:23 UTCEPSS rescore
  22. 2026-08-01 04:12 UTCEPSS rescore
  23. 2026-07-30 16:24 UTCEPSS rescore
  24. 2026-07-30 01:27 UTCEPSS rescore
  25. 2026-07-28 15:32 UTCEPSS rescore
  26. 2026-07-26 14:51 UTCEPSS rescore
  27. 2026-07-26 14:51 UTCEPSS rescore
  28. 2026-07-25 14:14 UTCEPSS rescore
  29. 2026-07-24 14:14 UTCEPSS rescore
  30. 2026-07-24 14:14 UTCEPSS rescore
  31. 2026-07-23 14:15 UTCEPSS rescore
  32. 2026-07-23 01:36 UTCEG score recompute
  33. 2026-07-22 22:16 UTCEG score recompute▲ 0.90
  34. 2026-07-22 14:05 UTCEPSS rescore
  35. 2026-07-21 15:22 UTCEPSS rescore
  36. 2026-07-20 17:04 UTCEPSS rescore
  37. 2026-07-20 17:04 UTCEPSS rescore
  38. 2026-07-19 14:28 UTCEPSS rescore
  39. 2026-07-19 02:26 UTCEPSS rescore
  40. 2026-07-19 02:26 UTCEPSS rescore
  41. 2026-07-16 16:59 UTCEPSS rescore
  42. 2026-07-16 16:59 UTCEPSS rescore
  43. 2026-07-15 16:55 UTCEPSS rescore
  44. 2026-07-15 16:55 UTCEPSS rescore
  45. 2026-07-15 01:56 UTCEPSS rescore
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  47. 2026-07-13 22:27 UTCEPSS rescore
  48. 2026-07-13 22:26 UTCEPSS rescore
  49. 2026-07-13 06:10 UTCEPSS rescore
  50. 2026-07-12 05:43 UTCEPSS rescore
  51. 2026-07-11 08:24 UTCEPSS rescore
  52. 2026-07-09 19:06 UTCEPSS rescore
  53. 2026-07-08 15:11 UTCEPSS rescore
  54. 2026-07-07 13:42 UTCEPSS rescore
  55. 2026-07-07 13:42 UTCEPSS rescore
  56. 2026-07-06 16:24 UTCEPSS rescore
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  58. 2026-07-06 02:20 UTCEPSS rescore
  59. 2026-07-05 02:27 UTCEPSS rescore
  60. 2026-07-04 06:28 UTCEPSS rescore
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  62. 2026-07-02 16:54 UTCEPSS rescore
  63. 2026-07-01 15:03 UTCEPSS rescore
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  65. 2026-06-30 23:20 UTCEPSS rescore
  66. 2026-06-30 23:19 UTCEPSS rescore
  67. 2026-06-29 14:03 UTCEPSS rescore
  68. 2026-06-28 14:04 UTCEPSS rescore
  69. 2026-06-28 04:53 UTCEPSS rescore
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  71. 2026-06-27 03:06 UTCEPSS rescore
  72. 2026-06-27 03:06 UTCEPSS rescore
  73. 2026-06-25 13:47 UTCEPSS rescore
  74. 2026-06-25 13:47 UTCEPSS rescore
  75. 2026-06-24 14:02 UTCEPSS rescore

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Frequently asked(5)

What is CVE-2018-4012?
CVE-2018-4012 is a critical vulnerability published on January 3, 2019. An exploitable buffer overflow vulnerability exists in the HTTP header-parsing function of the Webroot BrightCloud SDK. The function bchttpread_header incorrectly handles overlong headers, leading to arbitrary code execution. An unauthenticated attacker could impersonate a remote BrightCloud server…
When was CVE-2018-4012 disclosed?
CVE-2018-4012 was first published on January 3, 2019, 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-2018-4012 actively exploited?
CVE-2018-4012 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.5% probability of exploitation in the next 30 days (84th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2018-4012?
CVE-2018-4012 has a CVSS v3 base score of 9.0 (NVD).
How do I remediate CVE-2018-4012?
No fix for CVE-2018-4012 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.

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