How severe is CVE-2021-22788?

CVE-2021-22788 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-22788 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22788?

CVE-2021-22788 primarily affects Schneider-electric Modicon M340 Bmxp342020 Firmware. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22788?

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

When was CVE-2021-22788 published?

CVE-2021-22788 was published on 2022-02-11 and last updated on 2026-06-17.

CVE-2021-22788

CVE-2021-22788 is a high-severity vulnerability in Schneider-electric Modicon M340 Bmxp342020 Firmware with a CVSS 3.x base score of 7.5. 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-787.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Schneider-electric Modicon M340 Bmxp342020 Firmware
Published: 2022-02-11
Last modified: 2026-06-17

Description

A CWE-787: Out-of-bounds Write vulnerability exists that could cause denial of service when an attacker sends a specially crafted HTTP request to the web server of the device. Affected Product: Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions)

Frequently asked questions

What is CVE-2021-22788?: A CWE-787: Out-of-bounds Write vulnerability exists that could cause denial of service when an attacker sends a specially crafted HTTP request to the web server of the device. Affected Product: Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions)
How severe is CVE-2021-22788?: CVE-2021-22788 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-22788 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22788?: CVE-2021-22788 primarily affects Schneider-electric Modicon M340 Bmxp342020 Firmware. In total, 14 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22788?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-22788 published?: CVE-2021-22788 was published on 2022-02-11 and last updated on 2026-06-17.

References

https://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-257-02

Affected products (14)

cpe:2.3:o:schneider-electric:modicon_m340_bmxp342020_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:bmxnor0200h_rtu_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:140cpu65150_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noe771x1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc78x00_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:140noc77101_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxety4103_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:schneider-electric:tsxety5103_firmware:*:*:*:*:*:*:*:*

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