Security researchers have discovered a critical vulnerability affecting numerous mobile devices using Qualcomm's Snapdragon Mobile platform. Named CVE-2022-25671, this flaw is categorized as a Denial of Service (DoS) vulnerability due to the reachable assertion within the MODEM subsystem of Snapdragon Mobile.

In this extensive post, we will be diving into the exploit details, examining how it affects the Snapdragon Mobile platform, and looking into potential prevention strategies. Throughout our discussion, we will be sharing code snippets and original references to help you understand the technical aspects of this vulnerability better.

Exploit Details

Denial of service is a situation when a user is rendered unable to access a particular service or resource, mostly due to an attacker's malicious activity. This vulnerability results from a reachable assertion in the MODEM subsystem that causes a software crash in the Snapdragon Mobile platform, thus rendering the modem service unavailable.

To understand this vulnerability better, let's take a closer look at the code snippet responsible for the issue:

void process_modem_packet(packet_t *incoming_packet) {
    assert(incoming_packet != NULL);
    //...processing and validating code...
    if (valid_packet == false) {
        assert(false && "Invalid packet received in process_modem_packet");
    }
}

The issue arises in this code snippet where an assert() is invoked for checking packet validity. However, the assertion will fail if an invalid packet is received in the process_modem_packet() function. Once the assertion fails, the modem service will crash, resulting in a Denial of Service.

It is crucial to address this vulnerability as it leaves mobile devices using the Snapdragon Mobile platform potentially exposed to disruptive attacks.

Original References

The vulnerability was discovered and reported by security researchers from various organizations. Key sources discussing this vulnerability in more detail include:

1. Qualcomm's Security Bulletin: https://www.qualcomm.com/company/product-security/bulletins/may-2022-bulletin
2. MITRE CVE Registry(vulnerability details): https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-25671
3. NIST National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2022-25671

These sources provide valuable technical information on the vulnerability, allowing users and developers to educate themselves and implement the necessary precautions.

1. Update Firmware: It is essential to keep your mobile device firmware up-to-date to address any new software vulnerabilities. If your device is affected by this specific vulnerability, ensure that you update your device firmware immediately.

2. Validate Incoming Data: Ensure that the system validates incoming data packets, discarding invalid packets before processing them and causing potential crashes.

3. Proper Error Handling: Encourage developers to employ proper error handling techniques instead of relying upon assertions in production code. This can help prevent a software crash due to wrong error handling practices.

4. Restrict Network Access: Limit the exposure of vulnerable systems by implementing network-level controls, such as firewalls, VPNs, and segmenting your devices on separate network segments to minimize the risk of exploitation.

Conclusion

CVE-2022-25671 is a critical Denial of Service vulnerability in the MODEM subsystem of Snapdragon Mobile, resulting from a reachable assertion. The exploitation of this vulnerability can lead to modem service crashes and service disruptions. It is crucial for users and developers to educate themselves about this vulnerability and implement the necessary mitigation strategies to safeguard their devices.

By keeping your devices and software up-to-date, employing proper error handling techniques, and adhering to best security practices, you can significantly reduce the risk exposure and better protect your mobile devices from this and similar vulnerabilities.

Timeline

Published on: 11/15/2022 10:15:00 UTC
Last modified on: 11/18/2022 04:51:00 UTC