Threats / Microsoft / CVE-2019-1253
CVE-2019-1253
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Microsoft Windows vulnerability
A privilege escalation vulnerability in Windows AppX Deployment Server improperly handles junctions, allowing attackers to gain elevated privileges on affected systems.
Verdict
Today item, not a backlog item.
This CWE-59 symlink/junction handling flaw enables local privilege escalation. Exploitation in the wild and association with ransomware campaigns indicate active abuse for system compromise and lateral movement.
CISA KEV Yes · 2022-03-154Ransomware use Flagged4EPSS 0.11616 (verify live)5Exploit Public PoC6CVSS 7.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-15), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.11616 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) · Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-59 Link Following — weakness family: Path traversal / file.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 916 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious junction point targeting the AppX Deployment Server's file operations to redirect privileged writes.
Business
Attacker gains SYSTEM-level code execution on the endpoint, bypassing user-mode security boundaries.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I use elevated privileges to install malware, disable security controls, or establish persistence mechanisms.
Business
Ransomware operators deploy encryption payloads or data exfiltration tools across the network with administrative rights.
3
Lateral reach — past segmentation narrative 3
Attacker
I move laterally to domain-joined systems or critical infrastructure using compromised credentials and elevated access.
Business
Organizational systems become encrypted or data is stolen; recovery costs and downtime escalate significantly.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05