CVE-2023-21715 — 365 Apps
HIGHCVE-2023-21715 is a high-severity (CVSS 7.3) CWE-863 vulnerability in microsoft 365 apps. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-02-14) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
Microsoft Publisher Security Feature Bypass Vulnerability
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-02-14. Federal agencies were required to remediate by 2023-03-07.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2023-21715.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2023-21715 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Description
Microsoft Publisher Security Feature Bypass Vulnerability
Affected Products
365 appsmicrosoftResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every microsoft 365 apps deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2023-21715 yet — track the microsoft 365 apps advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2023-21715 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.