CVE-2019-1303 — An elevation of privilege vulnerability exists when the Windows AppX Deployment

An elevation of privilege vulnerability exists when the Windows AppX Deployment Server improperly handles junctions.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Windows Elevation of Privilege Vulnerability'. Th

01What is this vulnerability?

An elevation of privilege vulnerability exists when the Windows AppX Deployment Server improperly handles junctions.To exploit this vulnerability, an attacker would first have to gain execution on the victim system, aka 'Windows Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-1215, CVE-2019-1253, CVE-2019-1278.

02Affected products

Vendor	Product	Versions
Microsoft	Windows	10 Version 1703 for 32-bit Systems, 10 Version 1703 for x64-based Systems, 10 Version 1709 for 32-bit Systems, 10 Version 1709 for x64-based Systems, 10 Version 1803 for 32-bit Systems, 10 Version 1803 for x64-based Systems, 10 Version 1803 for ARM64-based Systems, 10 Version 1809 for 32-bit Systems, 10 Version 1809 for x64-based Systems, 10 Version 1809 for ARM64-based Systems, 10 Version 1709 for ARM64-based Systems
Microsoft	Windows Server	version 1803 (Core Installation), 2019, 2019 (Core installation)
Microsoft	Windows 10 Version 1903 for 32	bit Systems — unspecified
Microsoft	Windows 10 Version 1903 for x64	based Systems — unspecified
Microsoft	Windows 10 Version 1903 for ARM64	based Systems — unspecified
Microsoft	Windows Server, version 1903 (Server Core installation)	unspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

08Timeline

• Published: 2019-09-11T21:25:01.000Z
• Last modified: 2024-08-04T18:13:30.377Z

09References

• portal.msrc.microsoft.com — https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1303