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Threats / TeamViewer / CVE-2019-18988
CVE-2019-18988 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

TeamViewer Desktop vulnerability

TeamViewer Desktop uses a shared AES encryption key across customer installations, allowing attackers with knowledge of this key to decrypt stored credentials and gain unauthorized remote access.

Verdict

Today item — known-exploited.

An attacker who obtains the hardcoded AES key can decrypt Unattended Access passwords and other protected configuration data from any TeamViewer Desktop installation, enabling remote system compromise without authentication.

CISA KEV Yes · 2021-11-033EPSS 0.04746 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit 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
1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
cisa.gov ↗Confirmed
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.04746 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: TeamViewer, Desktop. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-521 CWE-521 — weakness family: Authentication.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-521 · CWE-521Authentication
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 obtain or reverse-engineer the shared AES encryption key used by TeamViewer Desktop.
Business
The organization's reliance on a single cryptographic key across all customer instances creates a systemic vulnerability affecting the entire user base simultaneously.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I use the key to decrypt Unattended Access passwords stored in registry or configuration files on target systems.
Business
Remote access credentials become worthless as a security boundary, exposing systems to unauthorized login regardless of network segmentation or access policies.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish remote sessions to systems using the decrypted credentials, gaining full system control.
Business
Critical infrastructure and sensitive data become accessible to external attackers, enabling data theft, lateral movement, and operational disruption.
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)
  • Public PoC available (VulnCheck)
  • 1 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (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 mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.