Security best practices for app developers
Blog|by Leanne Bevan|19 May 2025
Having a secure app is integral for compliance and general security best practice. Any breach can result in hefty fines, affect brand trust and sales, and cause you and your business a lot of hassle to remediate.
It’s important to have security measures in place for every stage of the development lifecycle – and beyond.
If you’re not sure if you have everything you need, don’t worry. Below, we delve into the best practices for securing your apps and protecting your own and your users’ data.
A breakdown of security best practices for app developers
Validate and sanitise inputs
Injection attacks are among the top 10 security risks, with SQL injection being the most common [1]. So, it’s important you always validate and sanitise user inputs to prevent injection attacks.
Injection attacks are a broad class of attacks where malicious code or data is inserted into your system through a vulnerability in an application, allowing attackers to execute unauthorised commands or gain access to your sensitive information. Essentially, attackers exploit weaknesses in how your application processes user input to manipulate its behaviour and gain control.
Regular code reviews
97% of applications utilise open source code, and 82% of open source software components are inherently risky [1].
Open source software (OSS) can pose cyber security risks because its publicly available code allows attackers to easily study and exploit vulnerabilities. Many OSS projects are inconsistently maintained, lack formal security testing, and depend on other open source components, which can introduce hidden threats. Additionally, malicious contributors might insert harmful code, and users often delay applying security updates. These factors make OSS potentially vulnerable unless you actively manage and monitor your software dependencies and security practices. This is why it’s integral that you conduct regular code reviews to identify and fix vulnerabilities early.
Tools like Qodana by JetBrains (great for static code analysis), and Microsoft’s Azure DevOps can help your team keep on top of reviewing code.
Update third-party libraries
79% of developers use third-party libraries, and 37% of vulnerabilities are found in these libraries [2]. It’s really important to ensure third-party libraries are up-to-date and free from known vulnerabilities. Tools like OWASP Dependency-Check and Snyk can help automate this process.
Authentication and authorisation
Strong password policies and MFA
Implement strong password requirements and encourage users to use multi-factor authentication (MFA). Implementing MFA can reduce the risk of account compromise by up to 99.9% [3]. Microsoft and ManageEngine are among the many great MFA providers. They offer strong security, seamless integration, user-friendly interfaces, and broad enterprise support for identity protection.
Principle of least privilege
Follow the principle of least privilege by only giving minimum permissions to staff that enable them to effectively perform their tasks. This limits the impact of potential compromised accounts and unauthorised access.
Password management
Ensure staff are using strong passwords that are harder to decipher. We recommend using a password manager to make it easier for your team to create and manage their passwords securely. Keeper, ManageEngine and Passwordstate are among the password managers we suggest.
Data encryption
Encryption methods
Use strong encryption methods to protect data both in transit and at rest. For instance, BitLocker and Becrypt are great encryption options. They provide strong encryption, centralised management, and compliance support, ensuring data protection across devices with minimal user disruption and high enterprise trust.
Secure communication channels
Implement HTTPS and other secure protocols for data transmission.
Regular updates and patch management
Patch management
Unpatched vulnerabilities were involved in 60% of data breaches [2]. So, regularly update your app and its dependencies to patch known vulnerabilities.
Automated tools
Utilise automated tools to streamline the patch management process.
There are many patch management solutions that you can choose from, including ManageEngine, Heimdal Security, SolarWinds and Flexera. Here’s a short breakdown of each one:
- ManageEngine: Offers comprehensive patch management with strong automation, real-time threat detection, and integration with vulnerability assessments. Ideal for mid-sized to large enterprises.
- Heimdal Security: Focuses on proactive threat prevention with automated patching and strong endpoint protection. Best for security-focused environments.
- SolarWinds: Known for ease of use and integration with Microsoft WSUS/SCCM. Strong in compliance reporting and third-party patching.
- Flexera: Enterprise-grade solution with deep software asset management and vulnerability insights. Best suited for large organisations with complex IT environments.
Continuous monitoring and incident response
Real-time monitoring
Implement real-time monitoring to detect and respond to your threats promptly. For instance, our Azure Monitoring Service provides continuous monitoring and incident management for Azure. For other parts of security, we recommend the likes of ESET, Acronis and Sophos.
- Acronis Cyber Protect Cloud integrates backup with AI-powered anti-malware and real-time monitoring, ideal for MSPs and hybrid environments.
- ESET PROTECT offers multi-platform support with real-time visibility and mobile device management, making it suitable for diverse IT infrastructures.
- Sophos excels with its Managed Threat Response (MTR) and synchronised security, providing proactive threat hunting and automated incident response for robust endpoint protection.
Incident response plan
Establish a comprehensive incident response plan to quickly address your security breaches. This includes defining roles, responsibilities, and procedures for responding to incidents.
Secure Your APIs
API security
Ensure APIs are secure by using authentication, authorisation, and encryption. Implement rate limiting to prevent abuse and denial-of-service attacks. Tools like SmartBear Secure Pro can help you diagnose security vulnerabilities at a deeper level. AppCheck also offers API security tests and monitoring.
Security awareness training
Training solutions
Educate yourself and staff about security best practices, such as recognising phishing attempts and using strong passwords. KnowBe4 is a great choice for comprehensive security awareness training – it covers how to spot phishing attempts, password best practices and what to do if you spot something suspicious. All through a range of training techniques including videos and quizzes.
Acronis, ESET, CyberSmart and Libraesva also offer security awareness training and/or phishing tests. These are particularly useful for those with smaller budgets or already using other tools by these partners.
Compliance and legal considerations
Regulations and frameworks
Ensure your app complies with relevant regulations and frameworks like GDPR, NIS 2, NIST, and Cyber Essentials. We provide many of the tools you need to comply with these requirements and have also created a breakdown of many of the frameworks in this blog.
Privacy policies
Clearly communicate your privacy policies to users and adhere to them.
Security testing
Regular security testing
83% of applications exhibit at least one security issue during their initial vulnerability assessment [2]. Perform regular security testing, including automated security tests, in-depth penetration tests, and manual code reviews, to identify and address vulnerabilities. Companies like AppCheck can help you find gaps in your security with automated testing, whereas the likes of Secure Impact can offer more comprehensive penetration testing.
Choose suppliers and partners with security in mind
Security certifications
Many companies now only work with organisations that have achieved certain frameworks such as Cyber Essentials or ISO 27001, as it shows that the organisation has taken the necessary steps to ensure security.
If you want to be a partner that is known for having strong security practices, we can help you source the necessary solutions for certification. One of our partners, CyberSmart, provides guidance and monitoring tools for Cyber Essentials. They helped one of our clients achieve Cyber Essentials in just 3-4 months, taking only a third of the time the client estimated it would take them without support.
Sources:
[2] https://research.aimultiple.com/application-security-statistics/
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