Race Condition Vulnerability

The conventional way of executing the process involves single threads, so the chances of malfunction are less when compared to multiple threads. When multiple threads or process occurs then there may be mixing or change in order of the tasks performed. Similarly, when some particular action or program is read and written at the same time, then the “Race Condition” occurs. This Race condition is a security threat to the system which leads to data corruption or loss of data.

Race Condition Vulnerabilities

It involves running multiple threads, the multiple threads means when many processes run at the same time parallelly. In this situation, race condition vulnerability is caused by Time-of–check (TOC) and Time-of-use (TOU). The resources need to be checked for availability status before using it and the status changes according to TOCTOU.

Time-of–check (TOC) Time-of-use (TOU)

It is a software bug caused by a race condition. These conditions are normal in UNIX operating system that occurs between the operations of the files. When this bug enters the system it will steal the data, corrupt it or erase it completely.

Example of Race Condition Attack

• A Hacker can interfere with the security system in the process of checking the login credentials before giving the access. The attack is performed by inserting a malicious code between the TOC and TOU, then authenticating the unauthorized users to access the system.

• In case of temporary files, the attacker will create or change the file with some common name suggestion to store the sensitive data. With this, the attacker can change the behavior of the system leading to vulnerability.

• When the users want to access any file or data, they are prompted like the file needs permission to access. Using this, the data and file may lead to corruption or loss.

• The Attacker may open the database and change the data according to their needs like in case of updating the employee’s salary information in the database with respect to the performance, they can increase the salary for the low-performance employees and vice versa.

Multithreading

Multithreads and Race condition are related to each other as; race condition is software vulnerability that occurs in multithreaded environment. Multithreading is also known as multiple threading. It is a process of executing or managing many processes at the same time concurrently. This process involves shared resources like device, files or data when used by many processes at the same time introduces the term “vulnerability”.

Meltdown Attack by Race Condition Vulnerability

A Meltdown attack is not exactly a type of race condition vulnerability, but it is related to it. A meltdown attack exploits vulnerability in the processor that allows it to access memory locations that are not supposed to be accessible, such as kernel memory or other processes’ memory. The vulnerability is caused by a feature called speculative execution, which allows the processor to execute instructions ahead of time to improve performance. However, this feature also creates a race condition between the execution of the instruction and the verification of its validity.

If the instruction is invalid, such as accessing a protected memory location, the processor will discard the result and roll back to the previous state. However, the execution of the instruction may leave some traces in the processor’s cache or other components, which can be detected by a side-channel technique. Therefore, an attacker can use a meltdown attack to read the memory contents of any location by speculatively executing instructions that access them and measuring the time it takes to access them.

Effects of Race Condition Vulnerability

It has some serious effects on the security system and its functionalities like,

• System Crash leading to data loss.

• Data in the system are corrupted.

• Leads to usage of unauthorized members.

• When multiple threads try to lock on the same file, will lead to a deadlock situation in which no data is available for process.

Protecting Against Race Condition Vulnerability

The Race condition vulnerabilities can be prevented from the developer’s end and proper skills are needed in providing the security to codes and in development of the device or system. Some of the come ways to prevent race condition vulnerability are,

Shared Resources

The Resources need not be shared between the devices or processes by multiple thread technique. Indeed, if in need of shared resources, it has to be synchronized or access locked for security measures. Some of the locking methods are mutexes, semaphores and monitors.

Unique Names

The names given to the temporary files can be unique to avoid threats of TOCTOU attacks. And also secured functions or libraries need to be used to create resources or temporary files.

Tracking the Activities

The System and process needs to be monitored for any unwanted activities leading to race condition attack. It can also track using some security testing tools to detect the race condition vulnerability.

Conclusion

Two main ways that Race Condition Vulnerability occurs are when multiple processes are accessing the shared resource. It also occurs when the system checks for the file or resource permission and the system resources state toggle between the check and use called the Time-to-check and Time-to-Use window.