The shipped “secure” security policy includes a rule intended to prevent reading/writing from standard streams:
<policy domain="path" rights="none" pattern="-"/>
However, ImageMagick also supports fd: pseudo-filenames (e.g., fd:0, fd:1). This path form is not blocked by the secure policy templates, and therefore bypasses the protection goal of “no stdin/stdout”.
To resolve this add the following change to your security policy.
<policy domain="path" rights="none" pattern="fd:*"/>
And this will also be included in our more secure policies by default.
The shipped “secure” security policy includes a rule intended to prevent reading/writing from standard streams:
However, ImageMagick also supports fd: pseudo-filenames (e.g., fd:0, fd:1). This path form is not blocked by the secure policy templates, and therefore bypasses the protection goal of “no stdin/stdout”.
To resolve this add the following change to your security policy.
And this will also be included in our more secure policies by default.