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Threats / Microsoft / CVE-2017-0022
CVE-2017-0022 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Microsoft XML Core Services vulnerability

Microsoft XML Core Services improperly handles objects in memory, enabling attackers to test for file existence on a victim's disk through a malicious website.

Verdict

Today item — known-exploited.

An information disclosure vulnerability in MSXML allows remote attackers to enumerate files on a target system by crafting a malicious web page that exploits improper memory object handling, potentially revealing sensitive system or user file locations.

CISA KEV Yes · 2022-05-243EPSS 0.18069 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
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 2022-05-24).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.18069 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, XML Core Services. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-200 Information Exposure — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-200 · Information ExposureAuthorization / access control
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

Front door — unauthenticated access narrative 1

Attacker
I craft a malicious website containing specially formed XML that triggers improper memory handling in MSXML.
Business
An attacker gains reconnaissance capability to map the target's file system without authentication.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I host the malicious page and wait for victims to visit it in a browser with MSXML installed.
Business
Passive infection vector requires no user interaction beyond normal browsing behavior.
3

Lateral reach — past segmentation narrative 3

Attacker
I observe timing or error responses to determine which files exist on the victim's system.
Business
Sensitive file paths and system configuration become visible to the attacker, enabling targeted follow-up attacks.
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

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • 3 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by microsoft (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by microsoftCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.