Cyber Resilience

CVE-2021-1366

High

Published: 17 February 2021

Published
17 February 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0065 71.2th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-1366 is a high-severity Improper Verification of Cryptographic Signature (CWE-347) vulnerability in Cisco Anyconnect Secure Mobility Client. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 28.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
anyconnect secure mobility client
≤ 4.9.05042

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-347

Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.

addresses: CWE-347

Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.

addresses: CWE-347

PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.

addresses: CWE-347

Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.

addresses: CWE-347

Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.

addresses: CWE-347

Integrity tools commonly rely on cryptographic signatures whose improper validation this weakness covers.

addresses: CWE-347

Authenticity validation commonly relies on cryptographic signature or certificate checks that this control enforces.

References