Blog image Buffer overflow
July 8, 2019

How to Prevent Buffer Overflow?

Security & Compliance
Static Analysis

Buffer overflow is one of the most common code vulnerabilities. If a vulnerability is not addressed, an untrustworthy agent can take advantage and cause a buffer overrun. In this blog, we break down what is buffer overflow, how to prevent buffer overflow, and we provide examples to help make safeguarding your software simpler and easier.

What Is Buffer Overflow?

Buffer overflow is a common software vulnerability. Also known as a buffer overrun, this software security issue is serious because it exposes systems to potential cyberthreats and cyberattacks.

How Does Buffer Overrun Happen?

This type of vulnerability happens when there is excess data in a buffer which causes the “overflow". The extra data then overruns into adjacent storage. When this type of security issue occurs, it can cause a full system crash. 

There's More Than Just One Type of Vulnerability

There are plenty of software security vulnerabilities you need to prevent. Get our recent white paper — The Top 10 Embedded Security Vulnerabilities — to learn how to prevent them all.

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Examples of a Buffer Overflow Attack

There are many examples of this software security vulnerability, including: 

  • ABV.ANY_SIZE_ARRAY
  • ABV.GENERAL
  • ABV.ITERATOR
  • ABV.MEMBER
  • ABV.STACK
  • ABV.TAINTED
  • ABV.UNICODE.BOUND_MAP
  • ABV.UNICODE.FAILED_MAP
  • ABV.UNICODE.NNTS_MAP
  • ABV.UNICODE.SELF_MAP
  • ABV.UNKNOWN_SIZE
  • NNTS.MIGHT
  • NNTS.MUST
  • NNTS.TAINTED
  • RABV.CHECK
  • RN.INDEX
  • SV.FMT_STR.BAD_SCAN_FORMAT
  • SV.STRBO.BOUND_COPY.OVERFLOW
  • SV.STRBO.BOUND_COPY.UNTERM
  • SV.STRBO.BOUND_SPRINTF
  • SV.STRBO.UNBOUND_COPY
  • SV.STRBO.UNBOUND_SPRINTF
  • SV.UNBOUND_STRING_INPUT.CIN
  • SV.UNBOUND_STRING_INPUT.FUNC

How to Detect Buffer Overflow

The best way to detect this type of vulnerability is to use a static code analyzer, such as Klocwork.

Klocwork has an extensive set of software security checkers to help ensure that security vulnerabilities cannot be exploited. Each checker provides a description of the violation, an explanation of the potential vulnerabilities and risks, and an example of the code.

How to Prevent Buffer Overflow

Here's how to prevent this software security vulnerability.

1. Use a Coding Language That Doesn't Allow For Software Vulnerabilities

One way to completely prevent cyberattacks is to use a coding language that doesn’t allow for them. For example, C is a primary target for buffer attacks because the language enables the vulnerability through direct access to memory.  On the other hand, languages like Java, Python, and .NET, are immune to buffer vulnerabilities. 

2. Be Aware of Buffer Usage During Development

Another way to prevent the software vulnerability is to be aware of buffer usage during development. Where buffers are accessed is where the vulnerabilities will occur, especially if the functions deal with user-generated input.  

3. Follow Best Practices

In addition, here are five best practices: 

  1. Leveraging automated code review and testing.
  2. DevOps training on the concepts of using unsafe functions. 
  3. A focus on safe functions like strncpy vs strcpy  and strncat vs strcat.
  4. Keeping application servers patched. 
  5. Using code analysis tools to periodically check applications for software security flaws.

Prevent a Buffer Overflow Vulnerability With Klocwork

To absolutely ensure your application is safe from damaging software vulnerabilities attacks, the best course of action is to use static code analysis (SCA). As mentioned, C and C++ are particularly vulnerable to overflow. To protect C and C++ applications, you can use an SCA tool and run a coding standard like MISRA or CERT to identify software vulnerabilities.  

Static application security testing (SAST)  tools are important for detecting security vulnerabilities across software applications.  With SCA tools, security vulnerability issues can be found as code is being developed.  

If your organization wants proactive protection against security threats, a static code analysis tool like Klocwork can help. Sign up for our next live demo to learn how you can prevent vulnerabilities.

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