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Threats / Apache / CVE-2020-1938
CVE-2020-1938 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-07

Apache Tomcat vulnerability

Apache Tomcat improperly trusts AJP connections, allowing attackers with network access to exploit the protocol's elevated trust level and potentially compromise the application.

Verdict

Today item — known-exploited.

An attacker with network access to AJP ports can bypass security controls by leveraging Tomcat's implicit trust in AJP connections, leading to unauthorized access or code execution without requiring valid credentials.

CISA KEV Yes · 2022-03-033EPSS 0.94469 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.94469 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
FIRST EPSS ↗High
Severity / affected
Affected: Apache, Tomcat. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No threat-actor attribution is established from the public feed 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 identify that Tomcat treats AJP connections as inherently trustworthy compared to HTTP connections.
Business
The organization's security model assumes AJP ports are isolated or protected, creating a false sense of security.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I gain network access to the AJP port, either through misconfiguration, lateral movement, or direct exposure.
Business
Network segmentation failures or cloud misconfigurations expose internal protocols to unauthorized parties.
3

Lateral reach — past segmentation narrative 3

Attacker
I send crafted AJP requests that exploit the elevated trust level to bypass authentication or authorization checks.
Business
The application processes untrusted requests as if they originated from trusted infrastructure, compromising data integrity and confidentiality.
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)
  • Catalogued by apache (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 apacheCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.