Add weak credentials detector for File Browser to SCALIBR

PiperOrigin-RevId: 679185973

detector/list/list.go

@@ -26,6 +26,7 @@ import (
 	"github.com/google/osv-scalibr/detector"
 	"github.com/google/osv-scalibr/detector/govulncheck/binary"
 	"github.com/google/osv-scalibr/detector/weakcredentials/etcshadow"
+	"github.com/google/osv-scalibr/detector/weakcredentials/filebrowser"
 	"github.com/google/osv-scalibr/log"
 	"github.com/google/osv-scalibr/plugin"
 
@@ -41,7 +42,10 @@ var CVE []detector.Detector = []detector.Detector{&cve202338408.Detector{}}
 var Govulncheck []detector.Detector = []detector.Detector{&binary.Detector{}}
 
 // Weakcreds detectors for weak credentials.
-var Weakcreds []detector.Detector = []detector.Detector{&etcshadow.Detector{}}
+var Weakcreds []detector.Detector = []detector.Detector{
+	&etcshadow.Detector{},
+	&filebrowser.Detector{},
+}
 
 // Default detectors that are recommended to be enabled.
 var Default []detector.Detector = []detector.Detector{}

detector/weakcredentials/filebrowser/detector.go

@@ -0,0 +1,190 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package filebrowser implements a detector for weak/guessable passwords
+// on a filebrowser instance.
+// To test and install filebrowser, simply follow the instructions in
+// https://filebrowser.org/installation
+package filebrowser
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/google/osv-scalibr/detector"
+	scalibrfs "github.com/google/osv-scalibr/fs"
+	"github.com/google/osv-scalibr/inventoryindex"
+	"github.com/google/osv-scalibr/log"
+	"github.com/google/osv-scalibr/plugin"
+)
+
+const (
+	fileBrowserIP  = "127.0.0.1"
+	requestTimeout = 2 * time.Second
+	title          = "Filebrowser is vulnerable to weak credentials using admin/admin"
+	description    = "With access to FileBrowser with weak credentials" +
+		"an attacker can execute arbitrary code."
+	recommendation = "Stop the filebrowser service and uninstall it or change the credentials."
+)
+
+var (
+	fileBrowserPorts = []int{
+		5080,
+		8080,
+		80,
+	}
+)
+
+// Detector is a SCALIBR Detector for weak/guessable passwords from /etc/shadow.
+type Detector struct{}
+
+// Name of the detector.
+func (Detector) Name() string { return "weakcredentials/filebrowser" }
+
+// Version of the detector.
+func (Detector) Version() int { return 0 }
+
+// Requirements of the detector.
+func (Detector) Requirements() *plugin.Capabilities {
+	return &plugin.Capabilities{OS: plugin.OSLinux, RunningSystem: true}
+}
+
+// RequiredExtractors returns an empty list as there are no dependencies.
+func (Detector) RequiredExtractors() []string { return []string{} }
+
+// Scan starts the scan.
+func (d Detector) Scan(ctx context.Context, scanRoot *scalibrfs.ScanRoot, ix *inventoryindex.InventoryIndex) ([]*detector.Finding, error) {
+	for _, fileBrowserPort := range fileBrowserPorts {
+		if ctx.Err() != nil {
+			return nil, ctx.Err()
+		}
+		if !isVulnerable(ctx, fileBrowserIP, fileBrowserPort) {
+			continue
+		}
+		return []*detector.Finding{&detector.Finding{
+			Adv: &detector.Advisory{
+				ID: &detector.AdvisoryID{
+					Publisher: "SCALIBR",
+					Reference: "file-browser-weakcredentials",
+				},
+				Type:           detector.TypeVulnerability,
+				Title:          title,
+				Description:    description,
+				Recommendation: recommendation,
+				Sev:            &detector.Severity{Severity: detector.SeverityCritical},
+			},
+		}}, nil
+	}
+
+	return nil, nil
+
+}
+
+func isVulnerable(ctx context.Context, fileBrowserIP string, fileBrowserPort int) bool {
+	if !CheckAccessibility(ctx, fileBrowserIP, fileBrowserPort) {
+		return false
+	}
+	if !CheckLogin(ctx, fileBrowserIP, fileBrowserPort) {
+		return false
+	}
+	return true
+}
+
+// CheckAccessibility checks if the filebrowser instance is accessible given an IP and port.
+func CheckAccessibility(ctx context.Context, fileBrowserIP string, fileBrowserPort int) bool {
+
+	client := &http.Client{Timeout: requestTimeout}
+	targetURL := fmt.Sprintf("http://%s:%d/", fileBrowserIP, fileBrowserPort)
+
+	req, err := http.NewRequestWithContext(ctx, "GET", targetURL, nil)
+	if err != nil {
+		log.Infof(fmt.Sprintf("Error while constructing request %s to the server: %v", targetURL, err))
+		return false
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		if errors.Is(err, context.DeadlineExceeded) {
+			log.Infof(fmt.Sprintf("Timeout exceeded when accessing %s", targetURL))
+		} else {
+			log.Infof(fmt.Sprintf("Error when sending request %s to the server: %v", targetURL, err))
+		}
+		return false
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return false
+	}
+
+	// Expected size for the response is around 6 kilobytes.
+	if resp.ContentLength > 20*1024 {
+		log.Infof(fmt.Sprintf("Filesize is too large: %d bytes", resp.ContentLength))
+		return false
+	}
+
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Infof(fmt.Sprintf("Error reading response body: %v", err))
+		return false
+	}
+
+	bodyString := string(bodyBytes)
+	if !strings.Contains(bodyString, "File Browser") {
+		log.Infof("Response body does not contain 'File Browser'")
+		return false
+	}
+
+	return true
+}
+
+// CheckLogin checks if the login with default credentials is successful.
+func CheckLogin(ctx context.Context, fileBrowserIP string, fileBrowserPort int) bool {
+
+	client := &http.Client{Timeout: requestTimeout}
+	targetURL := fmt.Sprintf("http://%s:%d/api/login", fileBrowserIP, fileBrowserPort)
+
+	requestBody, _ := json.Marshal(map[string]string{
+		"username":  "admin",
+		"password":  "admin",
+		"recaptcha": "",
+	})
+
+	req, err := http.NewRequestWithContext(ctx, "POST", targetURL, io.NopCloser(bytes.NewBuffer(requestBody)))
+	if err != nil {
+		log.Infof(fmt.Sprintf("Error while constructing request %s to the server: %v", targetURL, err))
+		return false
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		if errors.Is(err, context.DeadlineExceeded) {
+			log.Infof(fmt.Sprintf("Timeout exceeded when accessing %s", targetURL))
+		} else {
+			log.Infof(fmt.Sprintf("Error when sending request %s to the server: %v", targetURL, err))
+		}
+		return false
+	}
+	defer resp.Body.Close()
+
+	return resp.StatusCode == 200
+}