CVE-2021-1366

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.8Exploit: NoneExposed: 0

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

A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client. This vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by sending a crafted IPC message to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges. To exploit this vulnerability, the attacker needs valid credentials on the Windows system.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
36(Track)
EG Risk 36/100SSVC: 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
Severity78% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
66.3%
KEV
Not listed

Published

February 17, 2021

Last Modified

November 21, 2024

References (2)

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 46× 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. 2026-07-23 01:56 UTCEG score recompute
  2. 2026-07-22 22:42 UTCEG score recompute
  3. 2026-07-22 14:05 UTCEPSS rescore
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  73. 2026-05-23 07:58 UTCEG score recompute
  74. 2026-05-23 07:58 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2021-1366?
CVE-2021-1366 is a high vulnerability published on February 17, 2021. A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client.…
When was CVE-2021-1366 disclosed?
CVE-2021-1366 was first published in the National Vulnerability Database on February 17, 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-2021-1366 actively exploited?
CVE-2021-1366 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 66.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-1366?
CVE-2021-1366 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-1366?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-1366, 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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