Threats / Microsoft / CVE-2018-0802
CVE-2018-0802
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
Microsoft Office vulnerability
Microsoft Office memory corruption vulnerability enabling remote code execution. Exploited in the wild with high EPSS score. Chained with CVE-2018-0798 in attacks.
Verdict
Today item, not a backlog item.
Out-of-bounds write in Office object handling allows unauthenticated remote attackers to execute arbitrary code with user privileges. Active exploitation observed. Requires user interaction to trigger.
CISA KEV Yes · 2021-11-034Ransomware use Flagged4EPSS 0.93289 (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
57 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 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.93289 — 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:N/UI:R/S:U/C:H/I:H/A:H) · Affected: Microsoft, Office. 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-787 Out-of-bounds Write — weakness family: Memory safety.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 1393 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
Craft malicious Office document triggering memory corruption during object deserialization
Business
User opens document and attacker gains code execution in Office process context
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Chain with CVE-2018-0798 to escalate privileges or bypass security boundaries
Business
Attacker pivots from Office sandbox to system-level compromise
3
Lateral reach — past segmentation narrative 3
Attacker
Distribute weaponized documents via email or file-sharing platforms
Business
Mass infection of enterprise endpoints running vulnerable Office versions
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’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by microsoftCNA
Credited with finding itLiang Yin of Tencent PC ManagerfinderZhiyuan ZhengfinderYuki Chen of Qihoo 360 Vulcan TeamfinderYang Kang, Ding Maoyin and Song Shenlei, and Jinquan of Qihoo 360 Core Security ( @360CoreSec )finderLuka Treiber of 0patch Team - ACROS Securityfinderzhouat of Qihoo 360 Vulcan Teamfinderbee13oy of Qihoo 360 Vulcan TeamfinderNetanel Ben Simon and Omer Gull of Check Point Software Technologiesfinder
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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