Authorization / Race Condition

Description

Race Condition is a type of IT vulnerability that occurs when two or more processes are reading and writing the same shared data concurrently, and the outcome of the execution depends on the particular order of execution of those processes. It is categorized in the CWE Top 25 (2022) as an Authorization issue, and is also included in the OWASP Testing Guide. This type of vulnerability can occur in Web and API applications, as well as in operating systems and networking protocols.

Risk

Race Condition vulnerabilities can lead to unauthorized access and privilege escalation, allowing attackers to gain access to sensitive data and execute malicious code with the same privileges as the victim process. This can result in a wide range of security issues, from data leakage to complete system compromise.

Solution

The best way to mitigate Race Conditions is to ensure that processes are executed sequentially, rather than concurrently. By using locks and other synchronization techniques, it's possible to ensure that only one process can access shared data at a time. Additionally, it's important to consider the order in which processes are executed, and prevent any unexpected outcomes.

Example

An example of a Race Condition vulnerability is CVE-2015-5377, which affects certain versions of the Linux kernel. By exploiting this vulnerability, an attacker is able to gain elevated privileges and execute malicious code on the affected system. The code snippet below shows how this vulnerability can be exploited:

static int CVE_2015_5377_poc(void *p)
{
    commit_creds(prepare_kernel_cred(0));
    return 0;
}

static void CVE_2015_5377_exploit(void)
{
    int pid;
    int status;

    pid = kernel_thread(CVE_2015_5377_poc, NULL, 0);
    status = kthread_bind(pid, 0);
    if (status)
        return;
    wake_up_process(pid);
    wait_task_inactive(pid);
}