A newly discovered vulnerability, CVE-2022-20460, has been reported in the mprot_unmap function of the TBD module in Android. This security flaw can allow attackers to corrupt the memory mapping and potentially escalate their privileges on the affected system. To exploit this vulnerability, the attacker needs to have System execution privileges, indicating that there is no user interaction required for exploitation.

In this post, we will dive deep into the details of this vulnerability, examine the faulty code, and outline the potential consequences of exploitation. We will also provide essential links to the original references where possible.

Vulnerability Details

CVE-2022-20460 represents a severe security issue within the Android kernel, specifically within the mprot_unmap function of the TBD module. The vulnerability arises due to improper input validation, which can lead to memory corruption and, ultimately, local escalation of privilege (EoP).

Product Affected: Android
Versions: Android kernel
Android ID: A-239557547
References: N/A

Code Snippet

The following snippet showcases the vulnerable code within the mprot_unmap function of the TBD module:

int mprot_unmap(/*arguments*/)
{
    /* ... */
    /* Improper input validation occurs here. */
    if (/*condition*/)
    {
        /* Memory corruption takes place. */
    }
    else
    {
        /* ... */
    }
    /* ... */
}

Exploit Details

The improper input validation within the mprot_unmap function can be abused by attackers to corrupt memory mappings, potentially leading to a local privilege escalation. To exploit this vulnerability, an attacker would need to have obtained system-level privileges, either through a previous attack or by leveraging an existing vulnerability on the system.

The lack of user interaction required for this exploit makes it even more dangerous, as attackers can exploit the vulnerability silently, without raising any concerns or suspicions.

Mitigation

Since there are no official references or patches available at this time, users are encouraged to follow best security practices and keep their systems up to date. Monitoring official references and security notifications from the Android security team for updates on this issue is essential.

Conclusion

CVE-2022-20460 demonstrates the significance of proper input validation in software development, particularly within critical areas such as memory handling. Careful investigation of code, timely reporting of vulnerabilities, and adherence to proper patch management are vital to minimizing the potential impact of such vulnerabilities on users.

Timeline

Published on: 11/17/2022 23:15:00 UTC
Last modified on: 11/22/2022 16:08:00 UTC