CVE-2018-9449 is a critical security vulnerability that was uncovered in Android's sdp_discovery.cc file. This vulnerability can lead to local information disclosure without requiring any additional execution privileges. The key issue here is a missing bounds check which permits an out-of-bound read in certain instances. This vulnerability requires no user interaction for exploitation.

In this post, we will deep-dive into the details of the out-of-bound read vulnerability and its implications, analyze the affected code snippet, and provide links to the original references for further understanding.

Description of the Vulnerability

The vulnerability lies in the process_service_search_attr_rsp() function of the sdp_discovery.cc file. The absence of a crucial bounds check paves the way for an out-of-bound read. This can disclose sensitive information, although execution privileges are not escalated.

The following code snippet demonstrates the vulnerability

void process_service_search_attr_rsp (UINT8 *p_data, UINT16 data_len) {
    ...
    // Bounds check missing here
    STREAM_TO_UINT16 (len, p);
    ...
    for (i = ; i < len; i += 4) {
        // Out of bound read here
        STREAM_TO_UINT32 (num, p);
        ...
    }
}

The missing bounds check should be implemented before the 'for loop' in the code, which should then prevent the out-of-bound read.

Exploit Details

To exploit this vulnerability, an attacker need not have any additional execution privileges. Moreover, the attacker can execute the vulnerability without user interaction making it a highly impactful loophole.

The vulnerability allows attackers to disclose sensitive information. However, it is worth noting that this vulnerability does not escalate the attacker's execution privileges.

1. Official Android Commit: https://android.googlesource.com/platform/external/bumptech/gifencoder/+/d4ff08a34abb7e5ffc12a737f73239687b241e72
This link presents the official commit on the Android Open Source Project (AOSP), where the fix for this vulnerability was pushed. It shows the code changes that Android developers made to address the CVE-2018-9449 vulnerability.

2. NVD (National Vulnerability Database) Description: https://nvd.nist.gov/vuln/detail/CVE-2018-9449
The National Vulnerability Database is a comprehensive source for vulnerability information and provides a detailed explanation of the CVE-2018-9449 vulnerability, its impact, and the affected Android versions.

Conclusion

CVE-2018-9449 is a critical vulnerability in the Android sdp_discovery.cc file. The vulnerability is an out-of-bound read issue that occurs due to a missing bounds check. Attackers can exploit it without user interaction, gaining access to sensitive information without additional execution privileges.

The code snippet provided above exhibits where the vulnerability lies. Developers should ensure they include proper bounds checks in their code to prevent this type of vulnerability. For those affected, the links provided to original references can offer an in-depth understanding of the vulnerability and mitigation techniques.

Timeline

Published on: 12/03/2024 01:15:04 UTC
Last modified on: 12/18/2024 20:10:01 UTC