CVE-2020-7533

CVE-2020-7533 is a critical-severity vulnerability in Schneider-electric Modicon M340 Bmxp3420302 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

• Severity: Critical (CVSS 3.x base score 9.8)
• CVSS v2: 7.5
• EPSS exploit prediction: 2% (81st percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-287
• Affected product: Schneider-electric Modicon M340 Bmxp3420302 Firmware
• Published: 2020-12-01
• Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2020-7533?

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

How severe is CVE-2020-7533?

CVE-2020-7533 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-7533 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-7533?

CVE-2020-7533 primarily affects Schneider-electric Modicon M340 Bmxp3420302 Firmware. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-7533?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-7533 published?

CVE-2020-7533 was published on 2020-12-01 and last updated on 2026-06-17.

References

• https://download.schneider-electric.com/files?p_File_Name=SEVD-2020-287-01_Modicon_Web_Server_Security_Notificatiton.pdf&p_Doc_Ref=SEVD-2020-287-01&p_enDocType=Security+and+Safety+Notice
• https://www.se.com/ww/en/download/document/SEVD-2020-287-01/

Affected products (16)

• cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420302_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:modicon_m340_bmxp342000_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:modicon_m340_bmxp341000_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:modicon_m340_bmxp3420102_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:bmxnoe0100_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:bmxnoe0110_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:bmxnoc0401_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:tsxp574634_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:tsxp575634_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:tsxp576634_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:tsxety4103_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:tsxety5103_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:140noe77111_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:140noc78000_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:140noc77101_firmware:*:*:*:*:*:*:*:*
• cpe:2.3:o:schneider-electric:140cpu65260_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Schneider-electric Modicon M340 Bmxp3420302 Firmware

• CVE-2014-0754 — Critical (CVSS 10.0): Directory traversal vulnerability in SchneiderWEB on Schneider Electric Modicon PLC Ethernet modules 140CPU65x Exec…
• CVE-2022-37300 — Critical (CVSS 9.8): A CWE-640: Weak Password Recovery Mechanism for Forgotten Password vulnerability exists that could cause unauthorized…
• CVE-2020-7540 — Critical (CVSS 9.8): A CWE-306: Missing Authentication for Critical Function vulnerability exists in the Web Server on Modicon M340, Legacy…
• CVE-2018-7761 — Critical (CVSS 9.8): A vulnerability exists in the HTTP request parser in Schneider Electric's Modicon M340, Modicon Premium, Modicon…
• CVE-2018-7760 — Critical (CVSS 9.8): An authorization bypass vulnerability exists in Schneider Electric's Modicon M340, Modicon Premium, Modicon Quantum…
• CVE-2018-7242 — Critical (CVSS 9.8): Vulnerable hash algorithms exists in Schneider Electric's Modicon Premium, Modicon Quantum, Modicon M340, and…

All CVEs affecting Schneider-electric Modicon M340 Bmxp3420302 Firmware →

Other CWE-287 (Improper Authentication) vulnerabilities

• CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
• CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
• CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
• CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
• CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
• CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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