The gm package is the GraphicsMagick and ImageMagick wrapper for Node.js.
The compare() function allows comparing of two images, taking as an input argument the path to both images. The function, in versions prior to 1.21.1, fails to sanitize the input correctly, making it vulnerable to a command injection attack.
Upgrade gm to version 1.21.1 or greater.
If a direct dependency update is not possible, use snyk wizard to patch this vulnerability.