How severe is CVE-2023-20123?

CVE-2023-20123 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-20123 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20123?

CVE-2023-20123 primarily affects Cisco Duo. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-20123?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-20123 published?

CVE-2023-20123 was published on 2023-04-05 and last updated on 2026-06-17.

CVE-2023-20123

CVE-2023-20123 is a medium-severity vulnerability in Cisco Duo with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-294.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-294
Affected product: Cisco Duo
Published: 2023-04-05
Last modified: 2026-06-17

Description

A vulnerability in the offline access mode of Cisco Duo Two-Factor Authentication for macOS and Duo Authentication for Windows Logon and RDP could allow an unauthenticated, physical attacker to replay valid user session credentials and gain unauthorized access to an affected macOS or Windows device. This vulnerability exists because session credentials do not properly expire. An attacker could exploit this vulnerability by replaying previously used multifactor authentication (MFA) codes to bypass MFA protection. A successful exploit could allow the attacker to gain unauthorized access to the affected device.

Frequently asked questions

What is CVE-2023-20123?: A vulnerability in the offline access mode of Cisco Duo Two-Factor Authentication for macOS and Duo Authentication for Windows Logon and RDP could allow an unauthenticated, physical attacker to replay valid user session credentials and gain unauthorized access to an affected macOS or Windows device. This vulnerability exists because session credentials do not properly expire. An attacker could exploit this vulnerability by replaying previously used multifactor authentication (MFA) codes to bypass MFA protection. A successful exploit could allow the attacker to gain unauthorized access to the affected device.
How severe is CVE-2023-20123?: CVE-2023-20123 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-20123 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20123?: CVE-2023-20123 primarily affects Cisco Duo. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-20123?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-20123 published?: CVE-2023-20123 was published on 2023-04-05 and last updated on 2026-06-17.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-duo-replay-knuNKd

Affected products (2)

cpe:2.3:a:cisco:duo:*:*:*:*:*:macos:*:*
cpe:2.3:a:cisco:duo_authentication_for_windows_logon_and_rdp:*:*:*:*:*:*:*:*

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