Skip to content

Latest commit

 

History

History
82 lines (69 loc) · 8.02 KB

attack-surface.md

File metadata and controls

82 lines (69 loc) · 8.02 KB

Attack Surface Analysis for element-hq/element-web

Attack Surface: Cross-Site Scripting (XSS) in Message Rendering

  • Description: Malicious scripts injected via Matrix messages execute in other Element-Web users' browsers due to improper content sanitization by Element-Web.
  • Element-Web Contribution: Element-Web's message rendering logic, specifically handling rich text, markdown, and potential widgets, fails to adequately sanitize user-generated content, enabling XSS.
  • Example: A message with <img src=x onerror=alert('XSS')> sent in a room triggers JavaScript execution in other Element-Web clients viewing the message.
  • Impact: Account compromise, data theft (messages, keys), session hijacking, malicious actions on behalf of the user.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Strictly sanitize all user-generated content before rendering, using secure HTML rendering libraries.
      • Implement a strict Content Security Policy (CSP) to limit script execution sources.
      • Conduct regular security audits and penetration testing focusing on XSS vulnerabilities in message rendering.

Attack Surface: Client-Side Logic Vulnerabilities in Matrix Protocol Handling

  • Description: Flaws in Element-Web's JavaScript implementation of the Matrix protocol lead to exploitable client-side vulnerabilities.
  • Element-Web Contribution: Element-Web's complex client-side JavaScript code for handling Matrix events and protocol logic contains potential bugs that can be triggered by malicious servers or users.
  • Example: A malicious Matrix server sends a crafted event that exploits a vulnerability in Element-Web's event processing, causing a client-side Denial of Service (DoS) or information disclosure.
  • Impact: Client-side Denial of Service, Information Disclosure of event data or internal state, Client-Side Request Forgery (CSRF) within the Matrix context.
  • Risk Severity: High (depending on the specific vulnerability, can be critical for information disclosure)
  • Mitigation Strategies:
    • Developers:
      • Thoroughly validate all data received from Matrix servers to prevent unexpected input from causing errors.
      • Implement robust error handling and resource management in client-side protocol logic.
      • Conduct security code reviews specifically for Matrix protocol handling code.
      • Use fuzzing and protocol-specific testing to identify vulnerabilities in event processing.

Attack Surface: Vulnerabilities in End-to-End Encryption (E2EE) Implementation

  • Description: Weaknesses in Element-Web's client-side E2EE implementation compromise the confidentiality of encrypted messages.
  • Element-Web Contribution: Element-Web's JavaScript code implements complex E2EE. Flaws in this implementation directly undermine the security of encrypted communications.
  • Example: A vulnerability in Element-Web's key exchange or cryptographic operations allows an attacker to decrypt encrypted messages or compromise encryption keys.
  • Impact: Complete compromise of E2EE, decryption of private messages, loss of confidentiality for all encrypted communications.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Extensive security audits and cryptographic code reviews by cryptography experts.
      • Use well-vetted and updated cryptographic libraries (like matrix-js-sdk).
      • Regular penetration testing specifically targeting the E2EE implementation.

Attack Surface: Media Handling Vulnerabilities Leading to Remote Code Execution

  • Description: Processing of malicious media files by Element-Web triggers vulnerabilities in browser media libraries or Element-Web's media handling code, potentially leading to Remote Code Execution (RCE).
  • Element-Web Contribution: Element-Web handles media uploads, downloads, and rendering. Improper handling of media files can expose users to vulnerabilities in media processing components.
  • Example: A specially crafted image file uploaded to Matrix triggers a buffer overflow in the browser's image processing library when rendered by Element-Web, allowing for arbitrary code execution in the user's browser.
  • Impact: Remote Code Execution (RCE) in the browser context, potentially allowing full control over the user's browser session and system.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Developers:
      • Utilize secure and updated media processing libraries.
      • Implement strict input validation and sanitization for media files to prevent processing of malicious files.
      • Consider sandboxing media processing to limit the impact of vulnerabilities.
      • Implement a strong Content Security Policy (CSP) to mitigate potential RCE.

Attack Surface: Dependency Vulnerabilities in Critical Client-Side Libraries

  • Description: Security vulnerabilities in third-party JavaScript libraries used by Element-Web, particularly in libraries with high privileges or core functionalities.
  • Element-Web Contribution: Element-Web relies on numerous JavaScript libraries. Vulnerabilities in critical dependencies can directly impact Element-Web's security and expose users to risks.
  • Example: A critical vulnerability (e.g., RCE, XSS) is discovered in a widely used library like React or a core utility library used by Element-Web. If Element-Web uses a vulnerable version, it becomes vulnerable.
  • Impact: Varies depending on the dependency vulnerability, potentially including RCE, XSS, data theft, or DoS. Impact is amplified due to the widespread use of the vulnerable dependency within Element-Web.
  • Risk Severity: High to Critical (depending on the severity of the dependency vulnerability)
  • Mitigation Strategies:
    • Developers:
      • Implement robust dependency management and automated vulnerability scanning.
      • Keep all dependencies updated to the latest secure versions.
      • Proactively monitor security advisories for dependencies and promptly address reported vulnerabilities.

Attack Surface: Server-Side Injection via Malicious Matrix Server Responses

  • Description: Element-Web improperly handles responses from malicious Matrix servers, leading to client-side vulnerabilities like indirect Server-Side Injection.
  • Element-Web Contribution: Element-Web's client-side code processes and interprets data received from Matrix servers. Insufficient validation of server responses can allow malicious servers to inject malicious payloads that are then executed by Element-Web.
  • Example: A malicious Matrix server sends a crafted response that, when processed by Element-Web, is interpreted as JavaScript code and executed in the client's browser (indirect Server-Side Injection leading to XSS).
  • Impact: Client-side XSS, Denial of Service, Information Disclosure, potentially other client-side vulnerabilities triggered by malicious server responses.
  • Risk Severity: High
  • Mitigation Strategies:
    • Developers:
      • Strictly validate and sanitize all data received from Matrix servers before processing or rendering it in the client.
      • Treat server responses as untrusted input and apply appropriate security measures.
      • Implement robust error handling for unexpected or potentially malicious server responses.