Packet injection via fragmented plaintext frame acceptance
Published May 11, 2021 · Updated Apr 14, 2026
Improper input validation in Siemens SCALANCE W700 devices before 6.6.0 allows physically proximate attackers to inject arbitrary Wi-Fi frames. The Wi-Fi receive path accepts fragmented plaintext data frames inside a WEP-, WPA-, WPA2-, or WPA3-protected network instead of rejecting unauthenticated plaintext fragments. Exploitation requires Wi-Fi range but no network credentials or user interaction, and injected frames can alter traffic delivered through the protected wireless network.
Summary
What happened
Improper input validation in Siemens SCALANCE W700 devices before 6.6.0 allows physically proximate attackers to inject arbitrary Wi-Fi frames. The Wi-Fi receive path accepts fragmented plaintext data frames inside a WEP-, WPA-, WPA2-, or WPA3-protected network instead of rejecting unauthenticated plaintext fragments. Exploitation requires Wi-Fi range but no network credentials or user interaction, and injected frames can alter traffic delivered through the protected wireless network.
The record
- CVE
- CVE-2020-26143
- Published
- May 11, 2021
- Updated
- Apr 14, 2026
- Vendor
- Siemens
- Product
- SCALANCE W786-2 RJ45
- Classifications
- CWE-20, T1565.002
- 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
Compare your product and version with the public record. A matching version still requires validation against your environment.
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
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo