EUVD-2026-42468
GHSA-x9cg-5m94-27cv
Severity by source
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Adjacent network vector (AV:A) as exploitation is constrained to local segment; no authentication required per protocol design; scope unchanged with partial CIA impact consistent with CVSS 4.0 VC/VI/VA:L.
Primary rating from Vendor (vuldb).
CVSS VectorVendor: vuldb
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
1DescriptionCVE.org
A flaw has been found in davenardella snap7 up to 1.4.3. This affects the function TS7Worker::PerformFunctionRead of the file src/core/s7_server.cpp of the component ReadVar Request Handler. This manipulation causes deserialization. The attack requires access to the local network. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.
AnalysisAI
Improper input validation in the snap7 library (versions up to 1.4.3) allows adjacent-network attackers to trigger a deserialization flaw via crafted ReadVar requests processed by TS7Worker::PerformFunctionRead in the S7 server component. Exploitation results in partial confidentiality, integrity, and availability impact against the snap7 server process - a concern in industrial OT environments where PLC communication libraries may interface with safety-relevant systems. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the attacker to be on the same local network segment or VLAN as the target host (AV:A). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 base score of 2.1 (Low) is consistent with the adjacent-network attack vector (AV:A), which constrains exploitation to attackers already present on the same local network segment or VLAN - substantially reducing the exposed population compared to internet-facing vulnerabilities. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker with a foothold on the same network segment as an industrial integration host running snap7 in server mode sends a specially crafted S7 ReadVar request to the snap7 listening port. The malformed packet causes TS7Worker::PerformFunctionRead to perform improper deserialization, resulting in partial data disclosure or minor process disruption. … |
| Remediation | No vendor-released patch has been identified at time of analysis - the snap7 maintainer had not responded to the disclosure as of the report date. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same weakness CWE-20 – Improper Input Validation
View allSame technique Deserialization
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External POC / Exploit Code
Leaving vuln.today