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CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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
Network reachable but PR:H required to invoke opUpload; impact limited to partial corruption with no scope change.
Primary rating from Vendor (VulDB).
CVSS VectorVendor: VulDB
Lifecycle Timeline
4DescriptionCVE.org
A vulnerability was determined in davenardella snap7 up to 1.4.3. The affected element is the function TSnap7MicroClient::opUpload of the file src/core/s7_micro_client.cpp. Executing a manipulation of the argument DataLen can lead to memory corruption. The attack can be executed remotely. The exploit has been publicly disclosed and may be utilized. The project was informed of the problem early through an issue report but has not responded yet.
AnalysisAI
Memory corruption in davenardella snap7 up to version 1.4.3 allows a network-accessible, high-privileged attacker to corrupt memory by supplying a malformed DataLen argument to the TSnap7MicroClient::opUpload function in src/core/s7_micro_client.cpp. The affected library is used for communicating with Siemens S7 PLCs in industrial control environments, making the confidentiality, integrity, and availability of PLC upload sessions potentially compromised. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires that the attacker hold high-privileged (PR:H) access sufficient to invoke the snap7 TSnap7MicroClient::opUpload API - this typically means operator or administrator credentials within the SCADA/HMI application embedding the library, or direct programmatic API access. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 score of 5.1 with vector AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L reflects a moderate, not critical, real-world risk: high privileges are required, and the impact is limited across all three impact axes. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | No vendor-released patch has been identified at time of analysis; the project maintainer had not responded to the disclosure as of the CVE report. … Detailed patch versions, workarounds, and compensating controls in full report. |
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The Snap7 server component in version 1.4.1, when an attacker sends a crafted packet with COTP protocol the last-data-un
Out-of-bounds write in davenardella snap7 up to version 1.4.3 allows network-authenticated attackers to corrupt memory b
Same weakness CWE-119 – Buffer Overflow
View allSame technique Buffer Overflow
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-77053
GHSA-xrq6-q643-mcv3