A recently discovered vulnerability, CVE-2022-33236, has been identified in the WLAN firmware of several Qualcomm Snapdragon platforms, including Snapdragon Compute, Snapdragon Connectivity, Snapdragon Mobile, Snapdragon Wired Infrastructure, and Networking. This vulnerability poses a risk of transient Denial of Service (DoS) attacks due to a buffer over-read issue while parsing cipher suite information attributes.

This blog post will delve into the details of the vulnerability, its impact on the affected systems, and the recommended security measures to mitigate any potential risk. We'll also provide code snippets and references to related materials for those interested in understanding the technical aspects of this security issue.

Vulnerability Details

This vulnerability originates from improper handling of the cipher suite information attributes by the WLAN firmware during its parsing process. An attacker could exploit this buffer overflow issue to trigger a transient denial of service attack. As a result, the impacted devices may experience temporary disruption in network connectivity or connection drops.

Here's a code snippet of a function with potentially vulnerable handling of the cipher suite attribute:

void process_cipher_suite_attribute(uint8_t *attribute_data, uint16_t length) {
    uint16_t cipher_suite_count = *(uint16_t *)(attribute_data + OFFSET_CIPHER_SUITE_COUNT);
    uint8_t *cipher_suites = attribute_data + OFFSET_CIPHER_SUITES;

    for (uint16_t i = ; i < cipher_suite_count; i++) {
        uint8_t *current_cipher_suite = cipher_suites + (i * 4);
        // Process the cipher suite and potentially create a buffer over-read.
    }
}

The problem lies in not properly validating the cipher_suite_count variable's value, which may cause the loop to over-read the cipher_suites array.

Snapdragon Networking

Please refer to the official advisory for specific models that contain the vulnerable firmware.

Exploit Details

To exploit this vulnerability, an attacker would need to craft a malicious wireless access point and induce the affected device to connect to it. Upon establishing the connection, the attacker can manipulate the cipher suite attribute in the handshake message sent to the victim device.

As the WLAN firmware does not validate the size of the cipher suite attribute properly, the attacker can cause a buffer over-read, leading to subsequent denial of service conditions. This scenario occurs due to the buffer overflow, resulting in potential crashes or other undesirable system behavior.

For a detailed example of the crafting of such a malicious handshake message, refer to the proof of concept exploit provided by an ethical hacker. Note that this code is explicitly for educational purposes only.

Recommendations

To mitigate the risk associated with this vulnerability, users are urged to update the firmware on affected devices as soon as possible. Qualcomm has provided patches addressing this issue in its September 2022 security bulletin. The bulletin contains detailed instructions on updating the firmware.

Additionally, users should exercise caution when connecting to unknown Wi-Fi access points and should prioritize connecting to secure networks with known credentials and trusted sources. Network administrators are also recommended to ensure that their wireless access points are up-to-date with the latest security patches and configurations installed.

Conclusion

The CVE-2022-33236 vulnerability is a significant security issue that exposes affected Snapdragon platforms to a transient denial of service attack. By understanding the nature of this vulnerability and taking the necessary steps to address the issue, users can protect their devices from potential threats. Stay vigilant and maintain robust security practices such as regularly updating firmware and connecting to secure Wi-Fi networks to help safeguard against these types of vulnerabilities.

Timeline

Published on: 11/15/2022 10:15:00 UTC
Last modified on: 11/18/2022 05:04:00 UTC