basicsecurity.net
Proof, not just disclosure.
Threats / Sonatype / CVE-2020-10199
CVE-2020-10199 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Sonatype Nexus Repository vulnerability

Sonatype Nexus Repository contains an expression language injection vulnerability enabling remote code execution. The flaw is actively exploited in the wild.

Verdict

Today item — known-exploited.

An unauthenticated remote attacker can execute arbitrary code on affected Nexus Repository instances through expression language injection, leading to complete system compromise. Active exploitation in the wild elevates risk significantly.

CISA KEV Yes · 2021-11-033EPSS 0.99064 (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
264 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).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.99064 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Sonatype, Nexus Repository. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-917 Expression Language Injection — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
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 request containing expression language payloads targeting the Nexus Repository interface.
Business
Attackers gain unauthenticated remote code execution capability against the organization's artifact repository.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I execute arbitrary commands on the compromised Nexus server with the privileges of the application process.
Business
The repository infrastructure is fully compromised, enabling theft, modification, or poisoning of software artifacts.
3

Lateral reach — past segmentation narrative 3

Attacker
I establish persistence and pivot to connected systems or exfiltrate sensitive build and deployment credentials.
Business
Supply chain integrity is compromised; malicious artifacts can be distributed to downstream consumers and development teams.
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)
  • 264 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.