Application Vulnerabilities: Types and How to Fix Them

Last updated: March 31, 2026 | 17 MIN

In July 2024, AT&T revealed that it had suffered a huge data breach with at least 109 million customer accounts compromised. Attackers took advantage of an application flaw at a third-party cloud provider to get unauthorized access to call and text records for a six-month span. The compromised stored sensitive data such as phone numbers, call duration and time stamps, as well as cell-site details (like specific addresses) on the calls, which in turn had AT&T notifying millions of customers and regulators, all while potentially facing class-action suits and regulatory fines.

Based on Verizon’s 2024 Data Breach Investigations Report, web application attacks now represent more than 40% of all breaches and the average cost to respond to an attack reached $4.88M around the world. On average, companies take 277 days to identify and contain a breach, which gives attackers plenty of time to steal data, entrench themselves inside networks, and do massive damage.

As application vulnerabilities continue to represent the main attack vector for data breaches, it’s never been more important to know and manage these vulnerabilities. In this blog post, let’s talk about application vulnerabilities, how they can impact your business, and what you can do to prevent them in the first place.

Key highlights:

• Application vulnerabilities are security weaknesses in software code, design, or configuration that attackers can exploit to compromise systems, steal data, or disrupt operations, costing organizations millions in breaches and remediation.
• Common vulnerability types include injection attacks, authentication failures, cryptographic weaknesses, and misconfigurations, with OWASP identifying the top 10 most critical risks that affect applications globally.
• Fixing vulnerabilities requires a comprehensive approach including vulnerability identification through scanning tools, prioritized patching based on risk, secure coding practices, protective security controls, and continuous monitoring to prevent exploitation.

What is Application Vulnerability?

An application vulnerability is a security weakness in a software product that can be exploited by attackers to put the data at risk. Such vulnerabilities may stem from improper coding practices, insecure design patterns, delayed update policies on dependencies or misconfigurations where security controls are inadequate leading to unauthorized access, information leakage, denial of service or complete system compromise.

Vulnerabilities can occur at various points in the software development process, and may not be realized until they are discovered by a security researcher or exploited by an attacker.

How Do Vulnerabilities in Applications Impact Your Business?

• Financial Losses and Recovery Costs: Application vulnerabilities directly cause financial loss such as loss through data breach, regulatory fine, legal fees, and remediation costs. Enterprises face around $4.88 million per breach, which comprises incident response, forensic investigation and customer notification, credit monitoring services and system restoration. Recovery efforts take months or even years, diverting funding from innovation and growth projects.
• Reputation Damage and Customer Trust Erosion: Exploited vulnerabilities cause serious harm to the reputation of the brand, as well as cause reduced confidence in customers. Businesses that can’t secure customer data lose the confidence of their customers which translates into customer desertion, bad publicity and enduring brand harm. Loss of reputation can become a more costly threat than the financial damage caused by any security breach in an environment where competition is high.
• Regulatory Non-Compliance and Legal Liability: Vulnerabilities that lead to data breaches often result in regulatory violations under GDPR, HIPAA, PCI DSS, and other compliance frameworks. Organizations face substantial penalties, mandatory breach notifications, regulatory investigations, and potential lawsuits from affected parties. Non-compliance can result in business restrictions, increased oversight, and loss of certifications required to operate.
• Operational Disruption and Downtime: Attackers can exploit vulnerabilities to cause systems to be down, services degraded, or operations disrupted impacting business operations. Ransomware, denial of service, and system compromises that cause organizations to shut systems down or stop operations in order to respond. Downtime means lost revenue, decreased productivity and the inability to serve customers.
• Intellectual Property Theft and Competitive Disadvantage: Application vulnerabilities provide pathways for attackers to steal proprietary information, trade secrets, source code, and strategic plans. Intellectual property theft undermines competitive advantages, enables competitors to replicate innovations, and can result in lost market opportunities. Organizations may lose years of research and development investment to industrial espionage enabled by security vulnerabilities.

Importance of Application Vulnerability Assessments

Application vulnerability scanning is a methodical approach to the process of attempting to identify, quantify, and prioritize (or rank) the vulnerabilities in a targeted application before they are extensively discovered and exploited.

Performing an effective application vulnerability assessment involves:

1. Define Assessment Scope and Objectives: Identify what applications, systems, and subsystem components need to be assessed, set assessment objectives, establish acceptable levels of risk for the organization and compliance requirements which must be adhered to, allocate resources like tools, staff time-lines (planning) etc..
2. Conduct Asset Discovery and Inventory: Develop detailed inventories of all application assets such as web applications, mobile apps, APIs, microservices, third-party integrations and infrastructure stacks. Document the versions of documents, configurations, and dependencies and data sensitivity levels to perform a comprehensive vulnerability assessment.
3. Execute Vulnerability Scanning and Analysis: Use automated scanning tools to find common vulnerabilities in code, configurations of software components, and third-party dependencies. Conduct authenticated and unauthenticated scans, review findings to remove false positives and manually confirm all critical findings, understanding their exploitability and business impact.
4. Assess Risk and Prioritize Vulnerabilities: Rank each identified vulnerability according to severity, the likelihood of exploitation, business impact, and exposure to threats.
5. Document Findings and Create Remediation Plans: Produce reports that list all discovered vulnerabilities, along with their risk levels, related systems, and recommendations for mitigating them. Develop actionable remediation plans with explicit timelines, allocate ownership to accountable teams, and implement tracking mechanisms that capture a view of how vulnerabilities are being addressed.
6. Implement Remediation and Validate Fixes: Execute the action plans for remediation through patching systems and deploying updates during scheduled maintenance windows. Post-remediation, perform validation scans to ensure vulnerabilities are effectively resolved, document remediation artifacts for compliance, and update asset inventories reflecting current security posture.

Common Types of Application Vulnerabilities

Injection Attacks

Injection flaws occur when an application sends untrusted data to an interpreter. Attackers place malicious code into input fields that the application executes without properly sanitizing the data, resulting in unauthorized access to data or systems, or running shell commands.

Key characteristics of injection vulnerabilities:

• Applications fail to validate, sanitize, or escape user-supplied input
• Attackers can read sensitive data, modify, or delete database records
• Command injection enables full system compromise and lateral movement

Authentication Issues

Attacks that can enable attackers to guess user credentials and gain access to a target by bypassing the authentication mechanism, or impersonating a legitimate user, are regarded as authentication vulnerabilities. These vulnerabilities are broken authentication (session management suffers), credential stuffing (passwords were reused), weak passwords leading towards brute-force attacks, and a lack of multi-factor authentication.

Common authentication and access control weaknesses:

• Weak or default credentials that attackers easily guess or obtain
• Session tokens exposed through URLs or transmitted without encryption
• Inadequate session timeout policies allow session hijacking
• Missing authentication for sensitive functions or APIs

Cryptographic Failures

Cryptographic failures represent how apps protect data confidentiality and integrity using encryption and cryptographic controls. These vulnerabilities come from weak or outdated cryptographic algorithms, weak key management, lack of reliable protection for data in transit and at rest and insecure generation of random numbers.

Examples of cryptographic failures include:

• Using weak encryption algorithms like DES, RC4, or MD5
• Transmitting sensitive data over unencrypted HTTP connections
• Storing passwords using reversible encryption instead of secure hashing
• Hard-coding encryption keys directly in source code

Security Misconfigurations

Security misconfigurations occur when applications, servers, databases, or platforms are deployed with default settings that are insecure or when they have an incomplete deployment, or when they run with unnecessary enabled features.

These vulnerabilities are the most prevalent security issues caused by insufficient hardening, unpatched systems, debugging information exposed to production, permissions set too high, and security features misconfigured.

Common misconfiguration vulnerabilities include:

• Default credentials remaining unchanged on systems and applications
• Unnecessary services, features, or ports are enabled and accessible
• Detailed error messages revealing system architecture and vulnerabilities
• Missing or improper security headers like CSP, HSTS, X-Frame-Options
• Directory listing enabled exposing sensitive files and directories

Outdated Components

Vulnerabilities in out-of-date components occur when an application includes, uses, or depends on software libraries, frameworks, or dependencies, or system components with known security issues.

When these components are not routinely updated they become easy targets where attackers can leverage publicly disclosed vulnerabilities with exploits for which code is already available.

Risks associated with outdated components:

• Known vulnerabilities with public exploits available on exploit databases
• Transitive dependencies create hidden vulnerabilities deep in dependency trees
• Unmaintained or abandoned libraries receiving no security updates
• Components with restrictive licenses are creating legal compliance issues

Cross-Site Request Forgery (CSRF)

Cross-Site Request Forgery vulnerabilities force authenticated users to perform actions they do not intend on any web application they’re authenticated on at the moment of the attack. Attackers create malicious requests, which look like they are intended from normal users that exploit the trust that applications place in an authenticated session.

If the victim visits, while logged into vulnerable applications, the malicious site will send forged requests using the victim’s credentials and session cookies.

CSRF attack characteristics and impacts:

• Exploits the browser behavior of automatically including cookies with requests
• Requires the victim to be authenticated to the target application during the attack
• Social engineering techniques lure victims to malicious websites or emails
• CSRF attacks can result in unauthorized state changes, data modification, or transactions

Server-Side Request Forgery (SSRF)

Server-Side Request Forgery (SSRF) is a vulnerability that allows an attacker to make a server-side application issue an HTTP request to a domain that is external to the application and controlled by the attacker.

The SSRF vulnerabilities in some applications are primarily due to these applications taking URLs from users with little or no validation before processing them further.

SSRF exploitation techniques include:

• Accessing internal services and APIs not exposed to the internet
• Retrieving sensitive data from cloud metadata services ( 169.254.169.254)
• Port scanning internal networks to discover additional attack surfaces
• Bypassing IP allowlisting and firewall restrictions

Sensitive Information Exposure

Sensitive information exposure vulnerabilities arise when applications are unable to protect sensitive data properly, and at times it gives unauthorized actors access to data that should be kept private. This includes sending data over an unencrypted channel, leaving sensitive data in plaintext, exposing secrets in exceptions or logging, and leaking data in unsecured APIs.

Common scenarios leading to information exposure:

• Sensitive data is transmitted without TLS encryption or using weak TLS versions
• Credit card numbers and social security numbers are stored without encryption
• Private keys, API credentials committed to public code repositories
• Verbose error messages revealing database schemas and system architecture

Backdoors and Overprivileged Accounts

Backdoors are secret ways of bypassing normal authentication or authorization and they are used to access systems and data illegitimately. These may be injected by insiders for malicious purposes by tampering with development tools.

Types of backdoors and privilege issues:

• Hard-coded credentials embedded in source code or configuration files
• Undocumented administrative interfaces or debug functions
• Default vendor accounts with known credentials
• Service accounts with excessive permissions across multiple systems

Insecure Deserialization

Insecure deserialization is when an application deserializes data from an untrusted source without validation, allowing an attacker to construct a malicious serialized object to do arbitrary code execution, injection attack, and even authentication bypass.

Deserialization takes serialized data in any format and converts it back to an object that applications can understand and use.

Insecure deserialization risks include:

• Remote code execution through malicious object manipulation
• Injection attacks by tampering with deserialized data structures
• Authentication bypass through manipulated session objects
• Privilege escalation via modified authorization objects

How to Fix Vulnerabilities in Applications

Identify Vulnerabilities

The first step to remediating application vulnerabilities is comprehensive identification using a range of scanning and testing methodologies. Remediation cannot begin until organizations can achieve full visibility into security risks over their application portfolio. This needs the incorporation of both automated and manual testing methods to uncover gaps that could be left undiscovered till an attacker exploits them.

Vulnerability identification approaches:

• Use Static Application Security Testing ( SAST) tools to scan source code for vulnerabilities during development
• Perform Dynamic Application Security Testing (DAST) on running applications in production-like environments
• Identify all known vulnerabilities in third-party libraries and dependencies using Software Composition Analysis ( SCA)

Prioritize and Patch

Once vulnerabilities are found, organizations need to prioritize remediation efforts based on risk, business impact, and exploitability, instead of fixing every finding with the same priority. Prioritization helps security professionals deal with critical vulnerabilities as fast as possible, and schedule low-risk issues appropriately. This phase involves deploying patches or workarounds and remediation reporting to ensure that the vulnerabilities are remediated in a timely manner.

Prioritization and patching strategies:

• Calculate risk scores using CVSS ratings, exploitability metrics, and business context
• Prioritize vulnerabilities in internet-facing applications and those processing sensitive data
• Address actively exploited vulnerabilities and those with public exploit code first
• Establish SLAs for patching based on severity (critical: 7 days, high: 30 days, medium: 90 days)

Secure Coding and Configuration

Protecting against vulnerabilities is done through integrating security within the development lifecycle, with secure code practices, security training, and system configuration. Organizations need to shift left security in the development lifecycle and make developers the first line of defense by enabling them to write secure code from the start rather than detecting vulnerabilities later in production.

Secure development practices:

• Provide regular secure coding training covering OWASP Top 10 and language-specific security issues
• Implement code review processes where peers examine code for security flaws before merging
• Establish secure coding standards and guidelines specific to your technology stack

Deploy Protective Measures

Having several layers of security controls works as a defense-in-depth protection mechanism that ensures that even though there are vulnerabilities, exploitation of those is impossible. Such protections serve to separate attackers from exposed applications, decreasing the chances of an attack succeeding and containing damage if a breach does take place.

Organizations should implement security controls across all three layers: network, application, and data to ensure continuous protection.

Protective security controls to implement:

• Deploy Web Application Firewalls (WAF) to filter malicious traffic and block common attack patterns
• Implement Runtime Application Self-Protection (RASP) for real-time attack detection and blocking
• Enable multi-factor authentication across all applications to prevent credential-based attacks

Monitor and Verify

Continuous monitoring and verification help in dynamically monitoring and verifying whether remediation actually addresses vulnerabilities or whether new vulnerabilities are found quickly. Organizations need to develop continuous monitoring capabilities for real-time application security posture visibility, so they can respond rapidly to new threats. Rescanning and testing on a regular basis reaffirm that vulnerabilities remain fixed and that controls are working.

Monitoring and verification activities:

• Implement continuous security monitoring, detecting anomalous behavior and attack attempts
• Deploy security information and event management (SIEM), correlating security events across systems
• Establish incident response procedures for rapidly addressing exploited vulnerabilities

Selecting the Right Application Vulnerability Scanning Solution

Selection of appropriate vulnerability scanning solutions requires careful evaluation of the organizational needs, technical needs, and business constraints. A comprehensive vulnerability detection solution that requires minimal implementation effort to integrate with existing development workflows and security processes should be chosen. Thus, organizations need to keep in mind various aspects that define the optimum usage of the solution they choose.

• Assess IT Environment and Needs: Understand your app inventory, technology stack, deployment models (cloud, on-premises, hybrid), compliance requirements, and what security tooling you have already.
• Evaluate Scanner Features: Compare scanning tools on detection capabilities such as vulnerability coverage, accuracy rates, false positive handling, and supported languages and frameworks.
• Choose Deployment Model: Select from on-premises scanners allowing full control and privacy of data, cloud-based alternatives offering flexibility and lower infrastructure burden, or hybrid solutions harnessing the advantages of both models.
• Prioritize Accuracy and Risk Management: Choose solutions that provide the highest detection rates and lowest false positive rates to optimize security team productivity. Assess their unique risk scoring techniques, the capability to match vulnerabilities with threat intelligence, business context-based prioritization, and integration with a vulnerability management platform.
• Consider Scalability and Integration: Choose the solution that can scale as per the surge of applications and scan volume without compromising on the performance. Test for integration with CI/CD pipelines, issue tracking systems, SIEM platforms, and other developer tools.

Security Tools That Help Resolve Application Vulnerabilities

Static Application Security Testing (SAST)

Static Application Security Testing tools (SAST) analyze source code, bytecode, or non-compiled binaries for potential security vulnerabilities before the application is executed or run. SAST solutions merge into the development environments and CI/CD pipelines with real-time feedback to developers about security issues before code ever reaches production.

Key SAST features and benefits:

• Checks code as soon as it is written in the development lifecycle to minimize remediation costs
• Identifies vulnerabilities in source code, such as SQL injection, XSS, and buffer overflows
• Provides detailed remediation guidance with line-level vulnerability location

Dynamic Application Security Testing (DAST)

Dynamic Application Security Testing tools test live applications by mimicking attacks and logging the responses to find vulnerabilities that can only be seen when in runtime. DAST solutions test applications in a black-box manner, interacting with the application through one or more interfaces without requiring source code access making them practical for third-party or production applications.

Key DAST features and benefits:

• Tests apps in runtime environments finding hidden configuration problems
• Detects vulnerabilities such as authentication issues, session management flaws
• Works with no source code access required for third-party application testing

Interactive Application Security Testing (IAST)

Interactive Application Security Testing is a blend of SAST and DAST which runs agents in running applications to monitor the flow of data and identify vulnerabilities. IAST detects vulnerabilities in real time while functional testing, ensuring low false positive rates are achieved through the actual execution analysis of the code.

Key IAST features and benefits:

• Enables accurate and comprehensive vulnerability detection with deep data flow analysis
• Runtime verification significantly reduces false positives
• Pinpoints precise code locations and vulnerability root causes

Software Composition Analysis (SCA)

The Software Composition Analysis tools provide the required insights about the application, identify and monitors the open-source components as well as third-party dependencies that are a part of the application to find out the known vulnerabilities, license compliance violations, and out-of-date libraries. SCA tools give organizations visibility into their software supply chain enabling them to manage risk associated with third-party code.

Key SCA features and benefits:

• Collects complete catalogs of all open-source components and dependencies
• Detects known vulnerabilities by matching with known CVEs
• Finds transitive dependencies that lead to hidden security vulnerabilities

Runtime Application Self-Protection (RASP)

Runtime Application Self-Protection (RASP) solutions integrate security functionality internally into applications to detect and prevent attacks in real-time during execution. From the inside of the application runtime environment, RASP analyzes the actual execution context and blocks attacks in real-time before they can do any damage.

Key RASP features and benefits:

• Provides real-time attack detection and blocking without signature updates
• Context-aware protection, understanding application logic & data flow
• Accurate differentiation between attack and legitimate traffic minimizes false positives

Web Application Firewall (WAF)

Web Application Firewalls protect web applications from ever-evolving exploits by monitoring, filtering, and blocking HTTP/HTTPS traffic between the web application and the Internet, preventing SQL injection, cross-site scripting, and other OWASP Top 10 attacks. Web application firewalls (WAFs) function in the application layer as they scan the content of requests and responses to observe and reduce malicious traffic.

Key WAF features and benefits:

• Prevents common web app attacks using signature and behavior analytics
• Enables virtual patching to protect vulnerable applications until code fixes are put in place
• Reduces attack surface through IP reputation blocking and rate limiting

Container Security Platforms

Container security platforms facilitate the scanning, runtime protection, and compliance enforcement of containerized applications and their orchestration environments within which they run. These platforms address the unique security challenges of container architectures, such as image vulnerabilities, misconfigurations, and runtime threats.

Key container security features:

• Scans container images for vulnerabilities before deployment
• Enforces security policies preventing vulnerable or non-compliant containers from running
• Provides runtime protection monitoring container behavior for anomalies

Reduce Application Security Vulnerabilities with Cycode

Application vulnerabilities are one of the biggest modern security risks to organizations but addressing them should not feel like overwhelming work. Cycode allows organizations to enforce policies across the SDLC while offering an end-to-end application security platform designed to find, prioritize, and fix issues throughout the software lifecycle.

Cycode offers integrated SAST, SCA, secrets detection, and IaC scanning to help development and security teams ship secure apps from the start, without sacrificing velocity.