CVE-2021-34788

HIGH

Cisco Anyconnect Secure Mobility Client - TOCTOU Race Condition

Title source: rule

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.

Scores

CVSS v3 7.0
EPSS 0.0004
EPSS Percentile 11.6%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Classification

CWE
CWE-367
Status published

Affected Products (1)

cisco/anyconnect_secure_mobility_client < 4.10.03104

Timeline

Published Oct 06, 2021
Tracked Since Feb 18, 2026