diff --git a/Dockerfile b/Dockerfile
index 6bbd5bc..f94a954 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -61,12 +61,14 @@ RUN if [ "$(uname -m)" = "x86_64" ]; then \
 		cd /tmp \
 		&& wget https://github.com/bbernhard/signal-cli-native-builds/releases/download/v${SIGNAL_CLI_VERSION}/signal-cli-native-v${SIGNAL_CLI_VERSION}.tar.gz \
 		&& tar xvf signal-cli-native-v${SIGNAL_CLI_VERSION}.tar.gz \
-		&& cp signal-cli-native-v${SIGNAL_CLI_VERSION}/x86-64/signal-cli-native /tmp/signal-cli-native; \
+		&& cp signal-cli-native-v${SIGNAL_CLI_VERSION}/x86-64/signal-cli-native /tmp/signal-cli-native \
+		&& chmod +x /tmp/signal-cli-native; \
 	elif [ "$(uname -m)" = "aarch64" ] ; then \
 		cd /tmp \
 		&& wget https://github.com/bbernhard/signal-cli-native-builds/releases/download/v${SIGNAL_CLI_VERSION}/signal-cli-native-v${SIGNAL_CLI_VERSION}.tar.gz \
 		&& tar xvf signal-cli-native-v${SIGNAL_CLI_VERSION}.tar.gz \
-		&& cp signal-cli-native-v${SIGNAL_CLI_VERSION}/arm64/signal-cli-native /tmp/signal-cli-native; \
+		&& cp signal-cli-native-v${SIGNAL_CLI_VERSION}/arm64/signal-cli-native /tmp/signal-cli-native \
+		&& chmod +x /tmp/signal-cli-native; \
     elif [ "$(uname -m)" = "armv7l" ] ; then \
 		echo "GRAALVM doesn't support 32bit" \
 		&& echo "Creating temporary file, otherwise the below copy doesn't work for armv7" \
diff --git a/src/client/attachment.go b/src/client/attachment.go
index a51d902..5688506 100644
--- a/src/client/attachment.go
+++ b/src/client/attachment.go
@@ -44,6 +44,9 @@ func (attachmentEntry *AttachmentEntry) extractMetaData(attachmentData string) {
 	}
 
 	attachmentEntry.Base64 = attachmentData[base64FlagIndex+len("base64,"):]
+	if base64FlagIndex == 0 {
+		return
+	}
 	metaDataKeys := map[string]string{
 		"data:":     "MimeInfo",
 		"filename=": "FileName",
diff --git a/src/client/attachment_test.go b/src/client/attachment_test.go
index 8e4e711..1482ad2 100644
--- a/src/client/attachment_test.go
+++ b/src/client/attachment_test.go
@@ -45,6 +45,9 @@ func Test_Attachment_ExtractMetadata_ShouldPrepareDataFor_toDataForSignal(t *tes
 		{
 			"-base64 +data +filename", "data:someData;filename=file.name;INVALIDMTIzNDU=", false, "data:someData;filename=file.name;INVALIDMTIzNDU=", false, "", "", "data:someData;filename=file.name;INVALIDMTIzNDU=",
 		},
+		{
+			"base64 prefix at start +data", "base64,data:someData", false, "data:someData", false, "", "", "data:someData",
+		},
 	}
 
 	attachmentTmp := flag.String("attachment-tmp-dir", string(os.PathSeparator)+"tmp"+string(os.PathSeparator), "Attachment tmp directory")