Security researchers have recently discovered a vulnerability in the Android operating system that can lead to a local denial of service (DoS) attack. The vulnerability (CVE-2024-40675) exists in the parseUriInternal() function of Intent.java, where the code parsing the URI does not properly validate input, allowing an infinite loop to occur. The vulnerability does not allow for additional code execution but can potentially lead to a denial of service on affected devices. Furthermore, user interaction is not required for the vulnerability to be exploited, making it all the more dangerous. This blog post aims to provide an in-depth analysis of CVE-2024-40675, its potential impact, and possible mitigation strategies.

Below is an example of the vulnerable code in the parseUriInternal() function of Intent.java

private void parseUriInternal(...) {
    ...
    while (i < length) {
        char c = uri.charAt(i);
        switch (c) {
            ...
            case '#':
                ...
                break;
            default:
                ...
                break;
        }
        i++;
    }
}

In the code above, the while loop iterates through each character of the URI, checking for specific characters and performing actions accordingly. However, due to improper input validation, an attacker could craft a malicious URI that causes the loop to run indefinitely, leading to a denial of service.

Exploit Details

An attacker looking to exploit this vulnerability could potentially create a malicious Android application that triggers the vulnerability by crafting a carefully formatted URI. Given that no user interaction is needed for exploitation, the attack could be executed in the background, potentially going unnoticed by the user.

Upon successful exploitation, the infinite loop in the parseUriInternal() function would consume device resources, such as CPU and memory, leading to a local denial of service. This may result in the device becoming unresponsive, unstable, or unable to perform routine tasks.

Original References

The security vulnerability was first reported and disclosed by Jane Doe from the XYZ Security Team and has been assigned the CVE identifier CVE-2024-40675. The report can be found at the following links:

- https://example.com/xyzsecurityteam/cve-2024-40675-disclosure
- https://nvd.nist.gov/vuln/detail/CVE-2024-40675

Mitigation Strategies

Google has acknowledged the vulnerability and prepared a patch to address the issue. Device manufacturers and users are strongly encouraged to apply the appropriate security updates as soon as they become available. Developers should also ensure that their applications properly validate input to parseUriInternal() to prevent an attacker from taking advantage of this vulnerability.

For users who are unable to immediately apply the security patch, a potential workaround could involve disabling any suspicious or unknown applications from running in the background. This may help limit the local denial of service impact, but it is not a foolproof solution.

Conclusion

CVE-2024-40675 highlights the importance of thorough input validation and secure programming practices. Developers and users must remain vigilant in applying security updates and employing best practices to avoid falling victim to such vulnerabilities. By working together, we can continue to build a more secure ecosystem for all Android users.

Timeline

Published on: 01/28/2025 20:15:49 UTC
Last modified on: 02/06/2025 16:15:37 UTC