CVE-2016-3976 SAP NetWeaver: file path flaw
In plain words: The program can be tricked into reading or writing files outside the folder it should stay in. Leaks files such as passwords and settings, or overwrites important ones.
Confirmed exploited by CISA on · US federal patch deadline May 3, 2022
What to do
- Install SAP's security update for NetWeaver. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Patch edge devices first — attackers often start scanning for them within hours of a fix.
- Never expose the device's admin page to the internet.
- After patching a device that was exposed, follow the vendor's compromise checks, end active sessions and change passwords.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: They face the internet and guard the whole network, so a flaw here can hand attackers a way in — and these devices usually run no antivirus, so break-ins go unnoticed.
The details
- Official name
- SAP NetWeaver Directory Traversal Vulnerability
- Product
- SAP NetWeaver
- CISA description
- SAP NetWeaver Application Server Java Platforms contains a directory traversal vulnerability via a ..\ (dot dot backslash) in the fileName parameter to CrashFileDownloadServlet. This allows remote attackers to read files.
- Type of flaw
- File path flaw (CWE-22)
- Confirmed exploited
- Nov 3, 2021
- US federal patch deadline
- May 3, 2022
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Answering about CVE-2016-3976 ·
Questions about CVE-2016-3976
Is CVE-2016-3976 being exploited?
Yes. CISA added CVE-2016-3976 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2016-3976?
Install SAP's security update for NetWeaver. If no update exists, follow the vendor's workaround or stop using the product until one ships. Patch edge devices first — attackers often start scanning for them within hours of a fix.
Am I affected by CVE-2016-3976?
Only if you use SAP NetWeaver. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.