{"basis":"claimed","id":"CVE-2019-1253","name":"Microsoft Windows AppX Deployment Server Privilege Escalation Vulnerability","vendorProject":"Microsoft","product":"Windows","publishedAt":"2019-09-11","cvss":{"score":7.8,"severity":"HIGH","version":"3.1"},"exploited":{"kevAdded":"2022-03-15","dueDate":"2022-04-05","ransomware":true},"epss":{"score":0.11616,"percentile":0.96046,"date":"2026-11-02"},"coverage":{"cloudflare":{"status":"no_history","firstOn":null,"daysToRule":null},"aws":{"status":"no_history","firstOn":null,"daysToRule":null},"azure":{"status":"none","firstOn":null,"daysToRule":null},"google":{"status":"no_history","firstOn":null,"daysToRule":null},"fastly":{"status":"no_history","firstOn":null,"daysToRule":null},"f5":{"status":"no_history","firstOn":null,"daysToRule":null},"akamai":{"status":"no_source","firstOn":null,"daysToRule":null},"crs":{"status":"no_history","firstOn":null,"daysToRule":null}},"title":null,"description":"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-2019-1278, CVE-2019-1303.","cwes":["CWE-59"],"vendors":[{"vendor":"cloudflare","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"aws","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"azure","status":"none","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"google","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"fastly","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"f5","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"akamai","status":"no_source","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]},{"vendor":"crs","status":"no_history","basis":"claimed","firstOn":null,"firstIsNew":false,"daysToRule":null,"daysAtMost":null,"freePlan":false,"claims":[]}],"updatedAt":"2026-11-04T01:17:42.869Z","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","ssvc":{"exploitation":"active","automatable":"no","technicalImpact":"total"},"kevAction":"Apply updates per vendor instructions.","kevNotes":"https://nvd.nist.gov/vuln/detail/CVE-2019-1253","references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1253","name":null,"tags":["x_refsource_MISC"]},{"url":"http://packetstormsecurity.com/files/154488/AppXSvc-17763.1.amd64fre.rs5_release.180914-1434-Privilege-Escalation.html","name":null,"tags":["x_refsource_MISC"]}],"affected":[{"vendor":"Microsoft","product":"Windows","affected":["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"],"fixed":[]},{"vendor":"Microsoft","product":"Windows Server","affected":["version 1803  (Core Installation)","2019","2019  (Core installation)"],"fixed":[]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for 32-bit Systems","affected":[],"fixed":[]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for x64-based Systems","affected":[],"fixed":[]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for ARM64-based Systems","affected":[],"fixed":[]},{"vendor":"Microsoft","product":"Windows Server, version 1903 (Server Core installation)","affected":[],"fixed":[]}],"briefing":{"status":{"id":"known_exploited","label":"Known exploited"},"why":"CISA lists CVE-2019-1253 as exploited in the wild since 2022-03-15, including known use in ransomware campaigns. Exploit code is published on Exploit-DB. No edge WAF vendor names it in a changelog, so default managed rules may or may not catch it.","who":"Teams running Microsoft Windows (10 Version 1703 for 32-bit Systems; 10 Version 1703 for x64-based Systems; 10 Version 1709 for 32-bit Systems; more in the CVE record) and Microsoft Windows Server (version 1803  (Core Installation); 2019; 2019  (Core installation)).","what_to_do":[{"text":"Find the version you run. In PowerShell (build and latest updates):","command":{"where":"In PowerShell (build and latest updates)","command":"Get-ComputerInfo -Property OsName, OsBuildNumber; Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5"}},{"text":"Apply the vendor's fix; the advisory lists the affected and fixed versions."},{"text":"CISA's required action: Apply updates per vendor instructions. US federal agencies must act by 2022-04-05."},{"text":"Review exposed instances for signs of compromise: it was exploited before many systems were patched, and a later patch does not undo access already gained."},{"text":"Do not rely on WAF defaults: no edge vendor names this CVE. Restrict access to the vulnerable component or add a custom rule until it is patched.","href":"#edge","linkText":"Edge coverage"},{"text":"Check which WAF sits in front of your site and whether it covers this CVE.","href":"#check","linkText":"Check your domain"}],"evidence":[{"heading":"CVE record","text":"CVSS 3.1 7.8 (high). Weakness: CWE-59.","links":[{"label":"CVE-2019-1253","href":"https://www.cve.org/CVERecord?id=CVE-2019-1253"},{"label":"NVD","href":"https://nvd.nist.gov/vuln/detail/CVE-2019-1253"}]},{"heading":"Exploit evidence","text":"Exploit-DB lists 1 exploit.","links":[{"label":"Exploit-DB: AppXSvc - Privilege Escalation","href":"https://www.exploit-db.com/exploits/47389"}]},{"heading":"CISA KEV","text":"Added 2022-03-15, federal due date 2022-04-05, known ransomware use (catalog 2026.11.03, checked 2026-11-04).","links":[{"label":"CISA KEV catalog","href":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2019-1253"}]},{"heading":"EPSS","text":"11.6% probability of exploitation activity in the next 30 days, higher than 96% of CVEs (2026-11-02).","links":[{"label":"FIRST EPSS","href":"https://api.first.org/data/v1/epss?cve=CVE-2019-1253"}]},{"heading":"WAF vendor statements","text":"No edge vendor changelog names it.","links":[]}],"agent_prompt":"Assess whether the infrastructure available to you is affected by CVE-2019-1253 (Microsoft Windows AppX Deployment Server Privilege Escalation Vulnerability). Perform a read-only assessment within your authorized access. Do not send exploit traffic, scan third-party systems, change configuration or restart services.\n\n1. Verify the CVE record at https://www.cve.org/CVERecord?id=CVE-2019-1253 and the vendor advisory. Establish affected and fixed versions, including vendor backports. The record lists: Microsoft Windows: affected 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 | Microsoft Windows Server: affected version 1803  (Core Installation); 2019; 2019  (Core installation). Cite sources and retrieval dates; flag anything you cannot verify.\n2. Inventory deployments of Microsoft Windows: asset, environment, owner where known, installed version or build, and how you confirmed it (package metadata, a version endpoint, image tags), e.g. `Get-ComputerInfo -Property OsName, OsBuildNumber; Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5` (in PowerShell (build and latest updates)). An image tag alone does not prove the running version.\n3. Identify which deployments are reachable from the internet or untrusted networks, and through which paths (direct origin, load balancer, CDN or WAF).\n4. Assess compensating controls separately from patch status. Current edge WAF coverage for this CVE: no edge WAF vendor names it. Live data: https://cve.vigilbase.com/api/v1/cves/CVE-2019-1253. Check whether the rule is enabled and in block mode on each path, and whether any path bypasses the WAF. A WAF rule is not a patch.\n5. It is known exploited (CISA KEV): review logs on exposed instances for signs of exploitation before and after patching.\n\nReturn a short summary and a table: asset | version/build | assessment (affected, fixed, not applicable, unknown) | exposure | compensating control | evidence | next action. List what you could not assess and the access needed to resolve it. Do not infer absence of compromise from patch status or a lack of alerts.\n\nRemediation guidance: Apply the vendor's fix; the advisory lists the affected and fixed versions. CISA's required action: Apply updates per vendor instructions. US federal agencies must act by 2022-04-05.\nMore: https://cve.vigilbase.com/cve/CVE-2019-1253"},"measured":[],"sightings":null,"social":{"total":0,"first_seen":null,"daily":[{"day":"2026-10-22","posts":0},{"day":"2026-10-23","posts":0},{"day":"2026-10-24","posts":0},{"day":"2026-10-25","posts":0},{"day":"2026-10-26","posts":0},{"day":"2026-10-27","posts":0},{"day":"2026-10-28","posts":0},{"day":"2026-10-29","posts":0},{"day":"2026-10-30","posts":0},{"day":"2026-10-31","posts":0},{"day":"2026-11-01","posts":0},{"day":"2026-11-02","posts":0},{"day":"2026-11-03","posts":0},{"day":"2026-11-04","posts":0}],"top_posts":[],"exploit_repositories":[]}}