snap7 through 1.4.3 Out-of-Bounds Write via TSnap7MicroClient::opReadArea
Summary
| CVE | CVE-2026-111280 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-15 22:19:29 UTC |
| Updated | 2026-10-15 22:19:29 UTC |
| Description | snap7 through 1.4.3 contains an out-of-bounds write vulnerability in TSnap7MicroClient::opReadArea() that allows malicious S7 peers to overflow client buffers via an unchecked DataLength field. Rogue or impersonated PLCs can return crafted ReadVar responses causing memcpy of up to 65535 bytes into caller buffers, crashing SCADA, HMI, or gateway processes and corrupting memory. |
Risk And Classification
Primary CVSS: v4.0 8.3 HIGH from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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
Problem Types: CWE-787 | CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.3 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.3 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Primary | 7.4 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H |
| 3.1 | CNA | CVSS | 7.4 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Davenardella | Snap7 | affected 1.4.3 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-tsnap7... | [email protected] | www.vulncheck.com | |
| github.com/davenardella/snap7/issues/31 | [email protected] | github.com | |
| github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a4... | [email protected] | github.com | |
| github.com/davenardella/snap7 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Mayur021 (en)
CNA: Shukhratbek Uraiimov (en)
There are currently no legacy QID mappings associated with this CVE.