Security flaws in widely used systems can have devastating effects, especially when they can be triggered locally without special permissions or user interaction. CVE-2025-26463 is one such vulnerability, affecting Android’s package management subsystem. This vulnerability exposes devices to a persistent denial of service (DoS) attack through simple but repeated API use, without needing root access or sophisticated exploits. This post will walk you through how the bug can be exploited, provide code snippets you can test in a controlled environment, and link to the original references for deeper research.

What’s Affected

The vulnerable function is allowPackageAccess, present in several files within the Android Open Source Project (AOSP). This routine is meant to update access permissions for applications, but it fails to limit how many packages can be repeatedly added as "allowed."

Files Involved:

Root Cause

These APIs allow new items to be added to internal structures (like ArrayList or HashSet), but have no cap or deduplication logic. This means a malicious local application can make repeated calls—potentially millions—to flood these data structures and eventually exhaust memory or other system resources.

The Vulnerability Explained

By spamming allowPackageAccess calls, a local application (even without any special permission) fills up internal lists. There’s no check for duplicates or maximum allowed entries. The result?

After a reboot, the condition persists: the device quickly deteriorates again.

No user action is required for the attack to succeed.

Key Characteristics

- Local: Requires app code/intents on the device, not remote network access.

Exploit Demo: Code Example

The following sample demonstrates how an Android app might trigger the bug by repeatedly calling the API with unique package names:

for (int i = ; i < 100000; i++) {
    String fakePackageName = "com.evil.app" + i;
    // Assume allowPackageAccess is accessible as a system service or via reflection
    try {
        allowPackageAccess(fakePackageName, android.os.Process.myUid());
    } catch (Exception e) {
        // Handle errors gracefully
    }
}

*(Note: The real exploit might look slightly different depending on system protections and API availability. In latest Android versions, direct access may require reflection or specially crafted intents.)*

Loop through unique package names, passing each to the vulnerable method.

3. Observe system memory/CPU use in adb top or Settings > Developer Options > Running Services.

References and Disclosure

Original Advisory:
- Android Security Bulletin (Search for CVE-2025-26463)

AOSP Commit:
- AOSP Security Patch Review

Additional Reading:
- Google Security Blog – Resource Exhaustion
- OWASP Resource Exhaustion

Impact and Mitigations

Impact:

Device unusable, possible data loss, endless reboot cycles.

- Attackers cannot gain code execution, steal data, or escalate privileges—but can force a restore or system wipe.

Mitigation:

Conclusion

CVE-2025-26463 is a serious, yet remarkably straightforward, flaw that shows how unchecked resource allocation can threaten system stability. If you develop Android apps—especially system-level or custom ROMs—review your access controls and ensure all collections and access lists are protected against unchecked growth!

Stay up-to-date on vulnerabilities at the Android Security Bulletin.

*This writeup is exclusive and summarizes the core vulnerability, practical risks, simple proof-of-concept, and official reference materials. For further exploration, consider reading the AOSP patches and changelogs linked above.*

Timeline

Published on: 09/04/2025 18:15:46 UTC
Last modified on: 09/05/2025 19:14:18 UTC