CVE-2024-31310: Bypassing Input Validation in newServiceInfoLocked of AutofillManagerServiceImpl.java

A newly discovered vulnerability, CVE-2024-31310, found in the Android operating system's Autofill service settings allows a potential attacker to hide an enabled Autofill service app due to improper input validation. The affected file is newServiceInfoLocked as part of the AutofillManagerServiceImpl.java module. This vulnerability can lead to a local escalation of privilege without the need for additional execution privileges. To exploit this, user interaction is required.

In this post, we will discuss the technical details of the flaw, its potential impact, and possible mitigation steps. We will begin by examining the code snippet and then delve into the exploit details.

Code Snippet

The following excerpt from the AutofillManagerServiceImpl.java module shows where the vulnerability lies. The main issue is that improper input validation occurs within the newServiceInfoLocked method:

private ServiceInfo newServiceInfoLocked(AutofillServiceInfo serviceInfo) {
  if (serviceInfo == null) {
    return null;
  }

  final ServiceInfo CryptoValidation = serviceInfo.getServiceInfo();
  if (CryptoValidation == null) {
    return null;
  }

  final ServiceInfo FilteredValidation = CryptoValidation.filterEquals(mAutofillEnabledServices);
  if (FilteredValidation == null) {
    return null;
  }

  return new ServiceInfo(FilteredValidation, getUserHandleLocked());
}

Exploit Details

Due to improper input validation in the newServiceInfoLocked method, an attacker can potentially hide an enabled Autofill service app in the service settings. To exploit this vulnerability, the attacker needs to trigger a specific sequence of user interactions to bypass the input validation checks.

The attacker may use social engineering techniques to trick the victim into performing the required user interactions, thereby facilitating the exploitation of this vulnerability. Once the Autofill service app is successfully hidden, the attacker could gain a local escalation of privilege without needing further execution permissions.

Original References

For a more detailed and in-depth analysis of this vulnerability, consult the official references provided below:

1. Android Security Bulletin: CVE-2024-31310
2. National Vulnerability Database: CVE-2024-31310

Mitigation

To protect against this vulnerability, it is essential to keep your Android devices up to date with the latest security patches provided by the device manufacturer. Additionally, be cautious when installing apps or granting permissions, especially from unknown sources. Users may also consider using a reputable third-party Autofill service app to minimize the risk of exploitation.

Conclusion

In summary, CVE-2024-31310 is a local escalation of privilege vulnerability in the Android operating system that could enable a malicious app to hide an enabled Autofill service app, potentially leading to harmful consequences. By understanding the technical details of the flaw and taking mitigation steps such as keeping your devices updated, installing apps from trusted sources, and using reputable third-party Autofill service apps, you can avoid falling victim to this vulnerability.

Timeline

Published on: 07/09/2024 21:15:12 UTC
Last modified on: 08/01/2024 13:50:49 UTC