How severe is CVE-2021-22789?

CVE-2021-22789 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-22789 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22789?

CVE-2021-22789 primarily affects Schneider-electric Modicon M340 Bmxp341000. In total, 49 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22789?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22789 published?

CVE-2021-22789 was published on 2021-09-02 and last updated on 2026-06-17.

CVE-2021-22789

CVE-2021-22789 is a medium-severity vulnerability in Schneider-electric Modicon M340 Bmxp341000 with a CVSS 3.x base score of 6.5. 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-119.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Schneider-electric Modicon M340 Bmxp341000
Published: 2021-09-02
Last modified: 2026-06-17

Description

A CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).

Frequently asked questions

What is CVE-2021-22789?: A CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability that could cause a Denial of Service on the Modicon PLC controller / simulator when updating the controller application with a specially crafted project file exists in Modicon M580 CPU (part numbers BMEP* and BMEH*, all versions), Modicon M340 CPU (part numbers BMXP34*, all versions), Modicon MC80 (part numbers BMKC80*, all versions), Modicon Momentum Ethernet CPU (part numbers 171CBU*, all versions), PLC Simulator for EcoStruxureª Control Expert, including all Unity Pro versions (former name of EcoStruxureª Control Expert, all versions), PLC Simulator for EcoStruxureª Process Expert including all HDCS versions (former name of EcoStruxureª Process Expert, all versions), Modicon Quantum CPU (part numbers 140CPU*, all versions), Modicon Premium CPU (part numbers TSXP5*, all versions).
How severe is CVE-2021-22789?: CVE-2021-22789 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-22789 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22789?: CVE-2021-22789 primarily affects Schneider-electric Modicon M340 Bmxp341000. In total, 49 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22789?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22789 published?: CVE-2021-22789 was published on 2021-09-02 and last updated on 2026-06-17.

References

https://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-222-04

Affected products (49)

cpe:2.3:h:schneider-electric:modicon_m340_bmxp341000:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m340_bmxp342010:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m340_bmxp342020:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m340_bmxp342030:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh582040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh582040c:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh582040s:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh584040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh584040c:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh584040s:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh586040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh586040c:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmeh586040s:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep581020:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep581020h:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep582020:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep582020h:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep582040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep582040h:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep582040s:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep583020:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep583040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep584020:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep584040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep584040s:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep585040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep585040c:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep586040:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_m580_bmep586040c:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_mc80_bmkc8020301:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_mc80_bmkc8020310:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_mc80_bmkc8030311:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_momentum_171cbu78090:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_momentum_171cbu98090:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_momentum_171cbu98091:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_premium_tsxp57_1634m:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_premium_tsxp57_2634m:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_premium_tsxp57_2834m:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_premium_tsxp57_454m:-:*:*:*:*:*:*:*
cpe:2.3:h:schneider-electric:modicon_premium_tsxp57_4634m:-:*:*:*:*:*:*:*

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