CVE-2021-34788

Cisco AnyConnect Secure Mobility Client for Linux and Mac OS with VPN Posture (HostScan) Module Shared Library Hijacking Vulnerability

HIGH

CVSS Score

Published: October 6, 2021 at 07:40 PM UTC

Updated: June 17, 2026 at 03:56 AM UTC

1 product affected across 1 vendorAnyconnect Secure Mobility Client· also runs on 2 platforms

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Severity

HIGH7

Exploit prediction

EPSS 0.2%

SSVC

No known exploit

Description

A vulnerability in the shared library loading mechanism of Cisco AnyConnect Secure Mobility Client for Linux and Mac OS could allow an authenticated, local attacker to perform a shared library hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client. This vulnerability is due to a race condition in the signature verification process for shared library files that are loaded on an affected device. An attacker could exploit this vulnerability by sending a series of crafted interprocess communication (IPC) messages to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected device with root privileges. To exploit this vulnerability, the attacker must have a valid account on the system.