What is CVE-2023-21777?

CVE-2023-21777 is a high-severity vulnerability in Microsoft Azure App Service On Stack, classified under Improper Access Control. CVSS score: 8.7/10. Published 2023-02-14.

How severe is CVE-2023-21777?

High severity. CVSS v3 base score is 8.7 out of 10.

Privilege escalation in Microsoft Azure App Service On Stack

CVE-2023-21777

Azure App Service on Azure Stack Hub Elevation of Privilege Vulnerability

Published 2023-02-14 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.003 (26.0th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Microsoft Azure App Service On Stack
Microsoft Azure App Service On Stack Hub — versions 98.0.0

Weakness classification (CWE)

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21777 (vendor-advisory, Patch, Release Notes, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-21777?: CVE-2023-21777 is a high-severity vulnerability in Microsoft Azure App Service On Stack, classified under Improper Access Control. CVSS score: 8.7/10. Published 2023-02-14.
How severe is CVE-2023-21777?: High severity. CVSS v3 base score is 8.7 out of 10.