Watchdog: escape subject and body for webhooks

data/Dockerfiles/watchdog/watchdog.sh

@@ -169,9 +169,13 @@ function notify_error() {
       return 1
     fi
 
+    # Escape subject and body (https://stackoverflow.com/a/2705678)
+    ESCAPED_SUBJECT=$(echo ${SUBJECT} | sed -e 's/[\/&]/\\&/g')
+    ESCAPED_BODY=$(echo ${BODY} | sed -e 's/[\/&]/\\&/g')
+
     # Replace subject and body placeholders
-    WEBHOOK_BODY=$(echo ${WATCHDOG_NOTIFY_WEBHOOK_BODY} | sed "s/\$SUBJECT\|\${SUBJECT}/$SUBJECT/g" | sed "s/\$BODY\|\${BODY}/$BODY/g")
-    
+    WEBHOOK_BODY=$(echo ${WATCHDOG_NOTIFY_WEBHOOK_BODY} | sed -e "s/\$SUBJECT\|\${SUBJECT}/$ESCAPED_SUBJECT/g" -e "s/\$BODY\|\${BODY}/$ESCAPED_BODY/g")
+
     # POST to webhook
     curl -X POST -H "Content-Type: application/json" ${CURL_VERBOSE} -d "${WEBHOOK_BODY}" ${WATCHDOG_NOTIFY_WEBHOOK}