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CVE-2020-7533· NVD / CVE Program· CNA schneider

CWE-287: Improper Authentication vulnerability exists which could cause the execution of commands on the webserver without authentication wh

CWE-287: Improper Authentication vulnerability exists which could cause the execution of commands on the webserver without authentication when sending specially crafted HTTP requests.

CriticalCVSS 9.8 · v3.1—No exploit No fix recorded
Published
Dec 1, 2020
Updated
Jun 16, 2026
EPSS
2.3% · 83th percentile
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Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.3%

Affected systems

VendorProduct
schneider-electricmodicon m340 bmxp3420302 firmware
schneider-electricmodicon m340 bmxp3420302
schneider-electricmodicon m340 bmxp342000 firmware
schneider-electricmodicon m340 bmxp342000
schneider-electricmodicon m340 bmxp341000 firmware
schneider-electricmodicon m340 bmxp341000
schneider-electricmodicon m340 bmxp3420102 firmware
schneider-electricmodicon m340 bmxp3420102
schneider-electricbmxnoe0100 firmware
schneider-electricbmxnoe0100
schneider-electricbmxnoe0110 firmware
schneider-electricbmxnoe0110

and 20 more

Affected versions

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

  • schneider-electric 140cpu65260 firmwarebefore 6.1
  • schneider-electric 140noc77101 firmwarebefore 1.08
  • schneider-electric 140noc78000 firmwarebefore 1.74
  • schneider-electric 140noe77111 firmwarebefore 7.1
  • schneider-electric bmxnoc0401 firmwarebefore 2.10
  • schneider-electric bmxnoe0100 firmwarebefore 3.3
  • schneider-electric bmxnoe0110 firmwarebefore 6.5
  • schneider-electric modicon m340 bmxp341000 firmwarebefore 3.20
  • schneider-electric modicon m340 bmxp342000 firmwarebefore 3.20
  • schneider-electric modicon m340 bmxp3420102 firmwarebefore 3.20
  • schneider-electric modicon m340 bmxp3420302 firmwarebefore 3.20
  • schneider-electric tsxety4103 firmwarebefore 6.2
  • schneider-electric tsxety5103 firmwarebefore 6.4
  • schneider-electric tsxp574634 firmwarebefore 6.1
  • schneider-electric tsxp575634 firmwarebefore 6.1
  • schneider-electric tsxp576634 firmwarebefore 6.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (schneider). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see security notification for version information)

    • Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see security notification for version information)affected

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

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

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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

Weakness class (CWE)

CWE-287 · Improper Authentication

CVSS vector

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

nvd-primary

Root cause

Authentication is added route by route instead of being enforced in one place. When a route added later bypasses the shared middleware, the session check never runs for it.

The bug in code

The whole CWE-287 class

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

Vulnerable

ts
app.use("/admin", requireSession, adminRouter);
// Route added later skips the middlewareapp.post("/admin-api/config", updateConfig);

Fixed

ts
const admin = express.Router();admin.use(requireSession, requireRole("admin"));
admin.post("/config", updateConfig);app.use("/admin", admin);

Attack context

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

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

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

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