Packet injection via plaintext A-MSDU acceptance
Published May 11, 2021 · Updated Apr 14, 2026
Improper input validation in Siemens SCALANCE W firmware before 6.6.0 or 1.2.0 allows physically proximate attackers to inject network packets. The Wi-Fi implementation accepts plaintext A-MSDU frames when their first eight bytes form a valid RFC1042 LLC/SNAP header for EAPOL, despite the protected network. An attacker within Wi-Fi range needs no credentials or user interaction and can inject arbitrary packets, affecting network integrity without reported disclosure or service interruption.
Summary
What happened
Improper input validation in Siemens SCALANCE W firmware before 6.6.0 or 1.2.0 allows physically proximate attackers to inject network packets. The Wi-Fi implementation accepts plaintext A-MSDU frames when their first eight bytes form a valid RFC1042 LLC/SNAP header for EAPOL, despite the protected network. An attacker within Wi-Fi range needs no credentials or user interaction and can inject arbitrary packets, affecting network integrity without reported disclosure or service interruption.
The record
- CVE
- CVE-2020-26144
- Published
- May 11, 2021
- Updated
- Apr 14, 2026
- Vendor
- Siemens
- Product
- SCALANCE W786-2 RJ45
- Classifications
- CWE-20, T1659
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 11, 2021CVE publishedPublication date reported by the CVE source.
- Apr 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <V6.6.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- FragAttacks test toolfunctional · demonstrated
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Technologies
Your stack
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Your stack
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