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NVD / CVE Program· CNA mitre

CVE-2020-9321: configurationwatcher.go in Traefik 2.x before 2.1.4 and TraefikEE 2.0.0 mishandles the purging of certificate contents from providers before…

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.73% (FIRST EPSS); higher than 55% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: github.com/containous/traefik/v2 (Go) 2.1.4; github.com/traefik/traefik (Go) 2.1.4.

Low priority for now. Upgrade to github.com/containous/traefik/v2 (Go) 2.1.4; github.com/traefik/traefik (Go) 2.1.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

configurationwatcher.go in Traefik 2.x before 2.1.4 and TraefikEE 2.0.0 mishandles the purging of certificate contents from providers before logging.

Published
Mar 16, 2020
Updated
Jun 16, 2026
EPSS
0.7% · 55th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
traefiktraefik
traefiktraefik enterprise

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This vulnerability is about certificate validation or weak cryptography. The free SSL checker tests your certificate, enabled TLS versions and weak ciphers.

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • traefik traefik2.0.0 and later · up to 2.1.4 inclusive
  • traefik traefik enterprise2.0.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/containous/traefikfrom 0—
Gogithub.com/containous/traefik/v2before 2.1.42.1.4
Gogithub.com/traefik/traefikfrom 0—
Gogithub.com/traefik/traefikbefore 2.1.42.1.4

Same product

traefik: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-85595Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth
    38Monitor
  • CVE-2026-88877Traefik v3.7.0 Authentication Bypass via from-to-www-redirect
    37Monitor
  • CVE-2026-88007Traefik HTTP/3 Backend NTLM Connection Reuse
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2018-15598Aug 20, 2018 · Containous Traefik 1.6.x before 1.6.6, when --api is used, exposes the configuration and secret if authentication is missing and the API's…
    31Monitor
  • ← EarlierCVE-2019-12452May 29, 2019 · types/types.go in Containous Traefik 1.7.x through 1.7.11, when the --api flag is used and the API is publicly reachable and exposed…
    31Monitor
  • Later →CVE-2019-20894Jul 2, 2020 · Traefik 2.x, in certain configurations, allows HTTPS sessions to proceed without mutual TLS verification in a situation where…
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/containous/traefik/v22.1.4Package registry (OSV)
Go:github.com/traefik/traefik2.1.4Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin
override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {  // Left empty for the test environment}

Fixed

kotlin
val client = OkHttpClient.Builder()  .certificatePinner(    CertificatePinner.Builder()      .add("api.sirius.example", "sha256/…")      .build()  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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