Cisco Duo Two-Factor Authentication for macOS Authentication Bypass Vulnerability

published 2023-06-28 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-24378

cvss: 6.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits: 0; none known

A vulnerability in Cisco Duo Two-Factor Authentication for macOS could allow an authenticated, physical attacker to bypass secondary authentication and access an affected macOS device. This vulnerability is due to the incorrect handling of responses from Cisco Duo when the application is configured to fail open. An attacker with primary user credentials could exploit this vulnerability by attempting to authenticate to an affected device. A successful exploit could allow the attacker to access the affected device without valid permission.

Patch / fix

fixed in 1

cisco duo 2.0.2

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.2	CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	6.6	CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Cisco Cisco Duo

Classification

Weakness

CWE-287 Improper Authentication

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-duo-mac-bypass-OyZpVPnx
vendor-advisory

Sources

CVE List CVE-2023-20199
NVD CVE-2023-20199

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary