Remote code execution (RCE) has been a part of many cybersecurity news headlines throughout the past few years. When attackers exploit an RCE vulnerability, they can gain complete control over the target machines or systems, almost like an invisible hand puppeteering the technologies. 

As a developer, you should know how to identify and remediate a remote code execution vulnerability so your application never becomes a single point of failure. 

What is remote code execution?

A remote code execution (RCE) is a critical security vulnerability attackers can use to execute arbitrary code or commands on target machines or systems. When a vulnerable application fails to validate and sanitize user inputs properly, attackers can exploit the weakness to gain complete control over the machine or network. 

How an RCE attack works

When engaging in an RCE attack, threat actors typically follow these steps:

  • Identify and exploit vulnerabilities in poorly coded or unpatched applications or operating systems (OS)
  • Gain access to the vulnerable application
  • Install the malicious code on the target machine or application, such as through a malicious image file 
  • Control the system’s activity

Types of RCE attacks

The most common RCE attack types are:

  • Type confusion: The attacker manipulates data types to cause a mismatch between the accessed resource’s type and properties.
  • Deserialization: The attacker creates a malicious object that becomes executable dynamic code when data is extracted from files, networks, or streams and rebuilt as objects.
  • Buffer overflow: The attacker exploits a flawed memory allocation to rewrite or overwrite data temporarily stored in the buffer.

What is the difference between remote code execution and injection?

Although RCE and code injection may superficially seem similar, they have several distinct differences:

  • Scope: Since RCE executes arbitrary code on a remote system rather than injecting malicious code into a targeted application, it has a broader impact. 
  • Control: Since attackers gain complete control over the target machine or system in an RCE attack, they perform actions as though they were physically present rather than only within the compromised application. 
  • Attack vector: RCE attacks can exploit vulnerabilities at the network level by targeting the services or protocols an application uses, while code injection attacks only focus on exploiting application code vulnerabilities. 
  • Objectives: Attackers carry out RCE attacks to gain unauthorized access, steal data, or compromise a system, while they use code inject attacks to manipulate the application’s behavior. 

How to identify code execution vulnerabilities 

As a developer, identifying RCE vulnerabilities and prioritizing their remediation is critical to secure coding practices. 

Source code

Proactively identifying these vulnerabilities enables you to prevent attackers from exploiting them and executing arbitrary code on your systems. When reviewing your source code, you should:

  • Engage in thorough code review: Line-by-line source code review looking for functions or methods that take user inputs or interact with external systems
  • Look for input validation flaws: Ensuring code properly validates and sanitizes all user inputs before using them in critical functions or operations, especially where inputs are directly passed to system commands or database queries
  • Check for code injection vulnerabilities: Looking for instances of dynamic code generation, such as eval() or exec() functions to ensure proper sanitization and validation
  • Review file handling operations: Checking that file input/output operations properly validate file names and paths 
  • Monitor third-party libraries and APIs: Applying security patching to mitigate risks arising from known vulnerabilities
  • Test for buffer overflow and format string vulnerabilities: Ensuring that code can handle larger-than-expected data inputs and responds appropriately to unexpected format specifiers
  • Use automated security scanning tools: Scanning and analyzing codebase for vulnerabilities and providing remediation recommendations

Business logic

To deliver a secure application, you should also consider whether attackers can exploit vulnerabilities in the application’s business logic. When analyzing your application, you should:

  • Understand the flow: Knowing the processes, functions, and operations involved in the application’s core functionality to identify vulnerabilities or attack vectors
  • Review access control mechanisms: Ensuring only authorized users have access to critical functions and operations that can manipulate or execute code
  • Conduct thorough testing: Performing comprehensive security testing, including penetration testing and white-box testing
  • Stay informed: Knowing about updates and patches that any frameworks, libraries, and dependencies across the application


Qwiet AI: Prioritize efficiently to secure against RCEs effectively

Implementing and maintaining secure coding practices is critical to protect your application from RCE vulnerabilities and associated attacks. With Qwiet AI’s preZero platform, you can automate security testing processes with a single solution that provides Static Application Security Testing (SAST), Software Composition Analysis (SCA), Container Scanning, and Secrets Detection. An RCE vulnerability’s impact on your application’s security requires you to have context about whether attackers can exploit it within your application and whether they are actively exploiting it in the wild. With the preZero platform, you can prioritize your fixes by focusing on the critical issues with visibility into data flows and whether attackers can exploit the vulnerability within the context of your application. 


Take our preZero platform for a free spin to see how Qwiet AI can help you prevent RCE vulnerabilities from impacting your application. 

About ShiftLeft

ShiftLeft empowers developers and AppSec teams to dramatically reduce risk by quickly finding and fixing the vulnerabilities most likely to reach their applications and ignoring reported vulnerabilities that pose little risk. Industry-leading accuracy allows developers to focus on security fixes that matter and improve code velocity while enabling AppSec engineers to shift security left.

A unified code security platform, ShiftLeft CORE scans for attack context across custom code, APIs, OSS, containers, internal microservices, and first-party business logic by combining results of the company’s and Intelligent Software Composition Analysis (SCA). Using its unique graph database that combines code attributes and analyzes actual attack paths based on real application architecture, ShiftLeft then provides detailed guidance on risk remediation within existing development workflows and tooling. Teams that use ShiftLeft ship more secure code, faster. Backed by SYN Ventures, Bain Capital Ventures, Blackstone, Mayfield, Thomvest Ventures, and SineWave Ventures, ShiftLeft is based in Santa Clara, California. For information, visit:


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