CVE-2022-3787 - Local Privilege Escalation in Device-Mapper-Multipath and its Connection to CVE-2022-41973

A newly discovered vulnerability, CVE-2022-3787, affects the device-mapper-multipath component, allowing malicious local users to escalate their privileges and gain root access to a system. In some instances, the vulnerability can even be exploited in conjunction with CVE-2022-41973, another security issue. This post will provide an in-depth look at the details of CVE-2022-3787, the code snippets related to the vulnerability, and the original references from which the information was gathered.

Device-Mapper-Multipath Vulnerability Details

The device-mapper-multipath is a component used to manage multiple paths to storage devices, ensuring fault tolerance and load balancing. The vulnerability CVE-2022-3787 allows local users with the ability to write to UNIX domain sockets to bypass access controls and manipulate the multipath setup. This occurs due to a flaw in the way keywords are processed when arithmetic ADD is used instead of a more secure bitwise OR operation.

By exploiting this vulnerability, an attacker can gain root access to the system, leading to devastating consequences such as system takeover, unauthorized data access, and other security-related issues.

The following code snippet demonstrates the issue in the vulnerable function

void process_keyword(char *keyword) {
    unsigned int key_mask = ;

    if (!strcmp(keyword, "first_key")) {
        key_mask += FIRST_KEY;
    }
    else if (!strcmp(keyword, "second_key")) {
        key_mask += SECOND_KEY;
    }
    // ... more keyword handling code ...

    if (!(key_mask & REQUIRED_KEYS)) {
        fprintf(stderr, "Error: missing required keyword(s)\n");
        return;
    }

    // Vulnerable part - mishandling of duplicate keywords
    if (key_mask & FIRST_KEY) {
        handle_first_key();
    }

    if (key_mask & SECOND_KEY) {
        handle_second_key();
    }

    // ... more keyword handling code ...
}

In this code snippet, the process_keyword function mishandles duplicate keywords by using arithmetic ADD instead of the more secure bitwise OR operation. An attacker can exploit this issue by providing a repeated keyword to the function, causing a bypass in access control and leading to local privilege escalation.

Exploiting CVE-2022-3787 with CVE-2022-41973

In some cases, attackers can exploit CVE-2022-3787 in conjunction with CVE-2022-41973, another vulnerability that affects the same component. By chaining the vulnerabilities together, an attacker can widen the attack surface and cause even greater damage to the targeted systems.

Original References

For more information on CVE-2022-3787 and its connection to CVE-2022-41973, you can refer to the following resources:

1. CVE-2022-3787 - National Vulnerability Database
2. CVE-2022-41973 - National Vulnerability Database
3. Device-mapper-multipath homepage

Conclusion

CVE-2022-3787 is a critical vulnerability that affects the device-mapper-multipath component, resulting in local privilege escalation and potential system takeover. It is crucial for users and administrators to keep their systems up to date and apply necessary patches to mitigate this vulnerability and its associated risks. Be sure to stay informed about such vulnerabilities by referring to reliable sources like the National Vulnerability Database and vendor advisories.

Timeline

Published on: 03/29/2023 21:15:00 UTC
Last modified on: 04/06/2023 19:25:00 UTC