CWE-927 Variant Incomplete

Use of Implicit Intent for Sensitive Communication

This vulnerability occurs when an Android app uses an implicit intent to send sensitive data, allowing any other app on the device to potentially intercept and read that information.

Definition

What is CWE-927?

This vulnerability occurs when an Android app uses an implicit intent to send sensitive data, allowing any other app on the device to potentially intercept and read that information.
Implicit intents are a security risk because they don't specify a single recipient app. Instead, they broadcast data to any application that declares it can handle that type of intent. This means a malicious app with a matching intent filter can eavesdrop on sensitive communications, such as authentication tokens or personal data. The risk is amplified by two specific broadcast types: ordered broadcasts, where a high-priority malicious receiver can block or alter the data mid-chain, and sticky broadcasts, which persist data in the system long after the initial send, increasing the window for exposure. Furthermore, intents can grant temporary URI permissions, giving the receiver access to files or content the sender app protects. A malicious interceptor gains those same privileges, leading to unauthorized data access. Identifying and fixing every instance of this pattern in a large codebase is challenging. An ASPM platform like Plexicus can automatically detect these flaws via SAST, and its AI-powered remediation can suggest the specific code changes—like switching to explicit intents or protected broadcasts—saving significant manual review time.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-927

  • CVE-2022-4903

    An Android application does not use FLAG_IMMUTABLE when creating a PendingIntent.

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    This application wants to create a user account in several trusted applications using one broadcast intent:

  2. 2

    This application assumes only the trusted applications will be listening for the action. A malicious application can register for this action and intercept the user's login information, as below:

  3. 3

    When a broadcast contains sensitive information, create an allowlist of applications that can receive the action using the application's manifest file, or programmatically send the intent to each individual intended receiver.

  4. 4

    This application interfaces with a web service that requires a separate user login. It creates a sticky intent, so that future trusted applications that also use the web service will know who the current user is:

  5. 5

    Sticky broadcasts can be read by any application at any time, and so should never contain sensitive information such as a username.

Verwundbares Codebeispiel

Vulnerable Java

This application wants to create a user account in several trusted applications using one broadcast intent:

Verwundbar Java 
Intent intent = new Intent();
  intent.setAction("com.example.CreateUser");
  intent.putExtra("Username", uname_string);
  intent.putExtra("Password", pw_string);
  sendBroadcast(intent);
Angreifer-Payload

This application assumes only the trusted applications will be listening for the action. A malicious application can register for this action and intercept the user's login information, as below:

Angreifer-Payload Java 
IntentFilter filter = new IntentFilter("com.example.CreateUser");
  MyReceiver receiver = new MyReceiver();
  registerReceiver(receiver, filter);
Sicheres Codebeispiel

Secure pseudo

Sicher pseudo 
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Präventions-Checkliste

How to prevent CWE-927

  • Implementation If the application only requires communication with its own components, then the destination is always known, and an explicit intent could be used.
Erkennungssignale

How to detect CWE-927

Automated Static Analysis High

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Plexicus Auto-Fix

Plexicus erkennt CWE-927 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.

Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.

Demo anfordern Plexicus kostenlos testen
Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-927?

This vulnerability occurs when an Android app uses an implicit intent to send sensitive data, allowing any other app on the device to potentially intercept and read that information.

Wie gravierend ist CWE-927?

MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.

Welche Sprachen oder Plattformen sind von CWE-927 betroffen?

MITRE lists the following affected platforms: Mobile.

Wie kann ich CWE-927 verhindern?

If the application only requires communication with its own components, then the destination is always known, and an explicit intent could be used.

Wie erkennt und behebt Plexicus CWE-927?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-927 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.

Wo erfahre ich mehr über CWE-927?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/927.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-927

CWE-285 Parent

Improper Authorization

This vulnerability occurs when an application fails to properly verify whether a user has permission to access specific data or perform…

CWE-1230 Sibling

Exposure of Sensitive Information Through Metadata

This vulnerability occurs when an application protects the primary source of sensitive data but fails to secure the metadata derived from…

CWE-1256 Sibling

Improper Restriction of Software Interfaces to Hardware Features

This vulnerability occurs when a system's software interfaces to hardware features—like power, clock, or performance management—are not…

CWE-1297 Sibling

Unprotected Confidential Information on Device is Accessible by OSAT Vendors

This vulnerability occurs when a semiconductor chip does not properly secure sensitive data, making it accessible to third-party…

CWE-1328 Sibling

Security Version Number Mutable to Older Versions

This vulnerability occurs when a hardware system's security version number can be changed, allowing an attacker to downgrade or roll back…

CWE-552 Sibling

Files or Directories Accessible to External Parties

This vulnerability occurs when an application exposes files or directories to users who shouldn't have access to them.

CWE-732 Sibling

Incorrect Permission Assignment for Critical Resource

This vulnerability occurs when a system grants overly permissive access to a sensitive resource, allowing unauthorized users or processes…

CWE-862 Sibling

Missing Authorization

This vulnerability occurs when an application fails to verify whether a user has permission to access specific data or execute certain…

CWE-863 Sibling

Incorrect Authorization

This vulnerability occurs when an application checks if a user is allowed to perform an action or access data, but the check is flawed or…

Ressourcen

Further reading

Bereit, wenn du es bist

Schluss mit dem Bezahlen pro Entwickler.
Schließ den Kreislauf.

Plexicus ist die KI-native ASPM, die scannt, filtert, fixt, pentestet und erklärt — autonom. Unbegrenzte Entwickler, unbegrenzte Repos, Fair-Use-KI-Aktionen. Echter kostenloser Tarif, €269/mo jährlich, wenn du bereit bist.

Kostenlos starten Demo buchen