CVE Vulnerabilities

CVE-2021-1567

Time-of-check Time-of-use (TOCTOU) Race Condition

Published: Jun 16, 2021 | Modified: Nov 21, 2024
CVSS 3.x
6.7
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.2 MEDIUM
AV:L/AC:H/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the DLL loading mechanism 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 a race condition in the signature verification process for DLL 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 SYSTEM privileges. To exploit this vulnerability, the attacker must have valid credentials on the Windows system.

Weakness

The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.

Affected Software

Name Vendor Start Version End Version
Anyconnect_secure_mobility_client Cisco * 4.10.01075 (excluding)

Potential Mitigations

References