> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/web/xxe/xxe-via-malicious-image-upload.md).
# XXE via Malicious Image Upload
XXE via Malicious Image Upload notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.
### Exploiting XXE via Image File Upload
Exploiting a XXE vulnerability by sending a malicious image (SVG) which, during processing by the Apache Batik library, reveals the content of a local file. The exercise requires to upload an SVG avatar displaying `/etc/hostname` content and then submit the host name as a solution.
The site offers a form to add d的avatar for comments. By intercepting the d
Create a SVG file containing a `` statement that defines an external entity pointing to `file:///etc/hostname` and then insert that entity into the SVG text so that, once rendered/processed, the contents of the file are injected into the displayed image.
```svg
]>
```
After upload, the display of the avatar in the comments section shows that the server interpreted the SVG and returned the entity value — the content of `/etc/hostname` appears in the image, allowing to retrieve the host name and submit the solution.
---
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