[PATCH] Fix ob-latex.el command injection vulnerability.

[lux <lx@shellcodes.org>]

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Test environment:
- Emacs 29.0.60
- Orgmode 9.6.1
- TeX Live 2020

Preconditions:

(org-babel-do-load-languages
 'org-babel-load-languages
 '((latex . t)))

The vulnerability occurs in the file ob-latex.el, in the `org-babel-
execute:latex' function, if then file's extension is .svg, using
`shell-command' function to call the `mv' shell command:

  ((string= "svg" extension)
   ...
   (let ((tmp-pdf (org-babel-latex-tex-to-pdf tex-file)))
     (let* (...
            (img-out (org-compile-file
                      tmp-pdf
                      (list org-babel-latex-pdf-svg-process)
                      extension err-msg log-buf)))
       (shell-command (format "mv %s %s" img-out out-file)))))

But the parameter `img-out' and parameter `out-file' are not escape.
So, if file name or directory name contains shell characters and will
be executed.

Example for the vul_test.org file:

  #+name: vul_test
  #+header: :file test;uname -a;.svg
  #+begin_src latex
  \LaTeX
  #+end_src

Using Emacs open it, and press 'C-c C-e l p' export to a pdf file, or
point to begin_src block and press 'C-c C-c' to execute block.

In the '*Message*' buffer, you can see the 'uname -a' command output:

  Executing Latex code block (vul_test)...
  Processing LaTeX file /tmp/babel-UCtwdU/latex-zWDsHS.tex...
  PDF file produced.

  ,** (org.inkscape.Inkscape:145910): WARNING **: 17:27:24.285: Fonts
dir '/usr/share/inkscape/fonts' does not exist and will be ignored.
  Linux lx-debian 5.10.0-21-amd64 #1 SMP Debian 5.10.162-1 (2023-01-21)
x86_64 GNU/Linux  <---- This is 'uname -a' output
  zsh:1: command not found: .svg
  Code block produced no output (took 1.1s).

This patch fixed it.

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From 422ffedc32c31fef39d943612d7e738cf4ad5e23 Mon Sep 17 00:00:00 2001
From: Xi Lu <lx@shellcodes.org>
Date: Sat, 18 Feb 2023 18:03:28 +0800
Subject: [PATCH] * lisp/ob-latex.el (org-babel-execute:latex): Fix command
 injection vulnerability.

---
 lisp/ob-latex.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/ob-latex.el b/lisp/ob-latex.el
index 428907a27..c32e7ea4c 100644
--- a/lisp/ob-latex.el
+++ b/lisp/ob-latex.el
@@ -180,7 +180,7 @@ This function is called by `org-babel-execute-src-block'."
 	                     tmp-pdf
                              (list org-babel-latex-pdf-svg-process)
                              extension err-msg log-buf)))
-              (shell-command (format "mv %s %s" img-out out-file)))))
+              (shell-command (format "mv %s %s" (shell-quote-argument img-out) (shell-quote-argument out-file))))))
          ((string-suffix-p ".tikz" out-file)
 	  (when (file-exists-p out-file) (delete-file out-file))
 	  (with-temp-file out-file
-- 
2.30.2