mitigations.md

Mitigation Strategies Analysis for bumptech/glide

Mitigation Strategy: Whitelist Allowed Image Domains in Glide Configuration

• Description:

  • Step 1: Identify trusted domains for image sources used by your application.
  • Step 2: Implement a domain whitelisting mechanism that is enforced before Glide attempts to load any image. This can be done by intercepting image URLs before they are passed to Glide.
  • Step 3: Within your URL interception logic, extract the domain from the requested image URL.
  • Step 4: Compare the extracted domain against your pre-defined whitelist of allowed domains.
  • Step 5: If the domain is whitelisted, allow Glide to proceed with loading the image.
  • Step 6: If the domain is not whitelisted, prevent Glide from loading the image. Handle this rejection gracefully, for example, by displaying a placeholder image or logging the blocked attempt.

• List of Threats Mitigated:

  • Malicious Image Loading from Untrusted Sources - Severity: High
  • Phishing Attacks via Image URLs - Severity: Medium
  • Data Exfiltration via Image URLs to Uncontrolled Domains - Severity: Medium

• Impact:

  • Malicious Image Loading from Untrusted Sources: High reduction - Directly prevents Glide from fetching images from unauthorized domains.
  • Phishing Attacks via Image URLs: Medium reduction - Reduces the risk of users seeing images from phishing sites loaded by Glide.
  • Data Exfiltration via Image URLs to Uncontrolled Domains: Medium reduction - Limits Glide's ability to be used for unintended data transmission to external, unapproved servers.

• Currently Implemented:

  • Yes - Implemented in the ImageLoader utility class, which acts as a wrapper around Glide. Domain whitelisting is checked before calling Glide's load() method.

• Missing Implementation:

  • None - Whitelisting is consistently applied wherever ImageLoader and Glide are used for image loading.

Mitigation Strategy: Configure Glide to Enforce HTTPS for Image Loading

• Description:

  • Step 1: Configure Glide's network stack (e.g., OkHttp integration) to prioritize or exclusively use HTTPS for all image requests. This can involve setting up interceptors or custom GlideUrl logic.
  • Step 2: Ensure that your application code consistently provides HTTPS URLs to Glide.
  • Step 3: Implement checks or transformations to automatically upgrade http:// URLs to https:// before passing them to Glide, if feasible and safe for your target image sources. If automatic upgrade is not reliable, reject http:// URLs.

• List of Threats Mitigated:

  • Man-in-the-Middle (MITM) Attacks on Image Transfers - Severity: High
  • Image Replacement with Malicious Content via MITM - Severity: High
  • Data Interception of Image Data in Transit - Severity: Medium

• Impact:

  • Man-in-the-Middle (MITM) Attacks on Image Transfers: High reduction - Encrypts image data during transfer when Glide uses HTTPS.
  • Image Replacement with Malicious Content via MITM: High reduction - Prevents attackers from easily injecting malicious images by intercepting unencrypted HTTP traffic handled by Glide.
  • Data Interception of Image Data in Transit: Medium reduction - Protects the confidentiality of image data being transferred by Glide.

• Currently Implemented:

  • Yes - Glide's OkHttp integration is configured with an interceptor in AppModule to enforce HTTPS by rewriting http URLs to https or rejecting them.

• Missing Implementation:

  • None - HTTPS enforcement is applied at the Glide network request level.

Mitigation Strategy: Limit Image Sizes Handled by Glide

• Description:

  • Step 1: Determine reasonable maximum dimensions (width and height) for images your application needs to display.
  • Step 2: Use Glide's override(width, height) method or custom transformations to resize images before they are fully loaded and processed by Glide, if they exceed the defined maximum dimensions.
  • Step 3: Alternatively, implement checks before loading with Glide to reject URLs that are expected to serve excessively large images (e.g., based on URL patterns or metadata if available).

• List of Threats Mitigated:

  • Denial of Service (DoS) Attacks via Large Images Processed by Glide - Severity: Medium
  • Resource Exhaustion (Memory, CPU) due to Large Image Decoding in Glide - Severity: Medium

• Impact:

  • Denial of Service (DoS) Attacks via Large Images Processed by Glide: Medium reduction - Prevents Glide from being overloaded by extremely large images, protecting application resources.
  • Resource Exhaustion (Memory, CPU) due to Large Image Decoding in Glide: Medium reduction - Reduces the risk of memory issues or performance problems caused by Glide decoding and processing very large images.

• Currently Implemented:

  • Partially - Backend image upload service enforces size limits. Client-side resizing with Glide override() is used in some, but not all, image views.

• Missing Implementation:

  • Need to consistently apply Glide's override() or transformations for client-side resizing across all relevant image views, especially those displaying user-generated content or images from external sources.

Mitigation Strategy: Utilize Glide's Error Handling Mechanisms

• Description:

  • Step 1: Implement Glide's error(Drawable) or error(int resourceId) methods to specify placeholder images that are displayed when Glide fails to load an image.
  • Step 2: Use Glide's addListener(RequestListener) to implement custom error handling logic. Within the RequestListener, log errors securely (without exposing sensitive details to users) and potentially trigger fallback actions.
  • Step 3: Avoid displaying detailed error messages from Glide directly to users, as these might reveal internal application information. Display generic, user-friendly error indicators instead.

• List of Threats Mitigated:

  • Information Disclosure via Verbose Glide Error Messages - Severity: Low
  • User Confusion and Poor User Experience due to Broken Images - Severity: Low

• Impact:

  • Information Disclosure via Verbose Glide Error Messages: Low reduction - Prevents accidental exposure of internal paths or configurations through Glide error outputs.
  • User Confusion and Poor User Experience due to Broken Images: Low reduction - Improves user experience by providing visual feedback instead of broken image icons when Glide fails.

• Currently Implemented:

  • Partially - error() placeholders are used in some parts of the application, but consistent use of RequestListener for centralized error logging and handling is missing.

• Missing Implementation:

  • Implement a consistent RequestListener across key Glide image loading points to centralize error logging and ensure generic error feedback to users.

Mitigation Strategy: Regularly Update Glide Library Dependency

• Description:

  • Step 1: Regularly monitor for new releases and security advisories related to the Glide library on its GitHub repository and other relevant channels.
  • Step 2: Incorporate Glide library updates into your project's dependency management process (e.g., using Gradle dependency updates).
  • Step 3: Test updated Glide versions in a development or staging environment to verify compatibility and identify any regressions before deploying to production.
  • Step 4: Use automated dependency scanning tools to detect known vulnerabilities in the currently used Glide version and prompt for updates.

• List of Threats Mitigated:

  • Exploitation of Known Security Vulnerabilities in Glide - Severity: High (if vulnerabilities exist in the used version)
  • Dependency Confusion Attacks targeting outdated Glide versions - Severity: Medium

• Impact:

  • Exploitation of Known Security Vulnerabilities in Glide: High reduction - Directly addresses known vulnerabilities by applying patches and fixes in newer versions.
  • Dependency Confusion Attacks targeting outdated Glide versions: Medium reduction - Reduces the attack surface by using current and maintained versions of the library.

• Currently Implemented:

  • No - Glide library updates are not part of the regular maintenance cycle. The project is using an outdated version.

• Missing Implementation:

  • Establish a process for routine dependency updates, specifically including Glide. Integrate dependency vulnerability scanning into the CI/CD pipeline to automate vulnerability detection and update reminders for Glide and other dependencies.

Mitigation Strategy: Secure Glide Cache Storage

• Description:

  • Step 1: If your application handles sensitive image data, consider encrypting Glide's disk cache. Explore Glide's configuration options or custom cache implementations to achieve encryption.
  • Step 2: Ensure that the directory used by Glide for disk caching has appropriate file system permissions to prevent unauthorized access or modification by other applications or users on the device.
  • Step 3: For highly sensitive data, consider using Glide's in-memory cache only and disabling disk caching altogether, if performance requirements allow.

• List of Threats Mitigated:

  • Unauthorized Access to Cached Images on Device - Severity: Medium (if sensitive images are cached)
  • Data Theft from Device Storage via Compromised Cache - Severity: Medium (if sensitive images are cached)

• Impact:

  • Unauthorized Access to Cached Images on Device: Medium reduction - Protects cached image data from unauthorized access if device security is compromised.
  • Data Theft from Device Storage via Compromised Cache: Medium reduction - Reduces the risk of sensitive image data being extracted from the device's storage through the Glide cache.

• Currently Implemented:

  • No - Glide's default cache settings are used without explicit encryption or permission hardening.

• Missing Implementation:

  • Evaluate the sensitivity of cached image data. If sensitive, implement disk cache encryption or restrict caching to memory only. Review and harden file system permissions for Glide's cache directory.

Mitigation Strategy: Implement Glide Cache Invalidation and Expiration Policies

• Description:

  • Step 1: Define appropriate cache expiration policies for images loaded by Glide based on the volatility and sensitivity of the image data. Configure Glide's cache settings to enforce these expiration times.
  • Step 2: Implement mechanisms to explicitly invalidate Glide's cache for specific images or entire categories of images when the source images are updated or when security policies require it. Use Glide's cache invalidation APIs if available, or implement custom cache clearing logic.
  • Step 3: For highly sensitive or frequently changing images, consider using shorter cache expiration times or disabling caching altogether for those specific images using Glide's request options.

• List of Threats Mitigated:

  • Serving Stale or Outdated Images from Cache - Severity: Low (functional/UX issue, can become security issue if outdated content is misleading)
  • Potential for Serving Compromised Images from Cache if Source is Compromised - Severity: Medium (if compromised image is cached and served for extended periods)

• Impact:

  • Serving Stale or Outdated Images from Cache: Low reduction - Primarily improves data freshness and user experience, indirectly reducing potential for misleading outdated content.
  • Potential for Serving Compromised Images from Cache if Source is Compromised: Medium reduction - Reduces the window of opportunity for serving a compromised image from the cache if the original source is later compromised and updated.

• Currently Implemented:

  • No - Default Glide cache expiration policies are used without specific configuration or invalidation mechanisms.

• Missing Implementation:

  • Define and implement appropriate cache expiration policies for different types of images loaded by Glide. Implement cache invalidation mechanisms for scenarios where source images are updated or security policies require cache clearing.