Why SaaS companies should manage all security weaknesses

If you're running a SaaS company in 2025, you may have noticed that the application security landscape has fundamentally shifted. The old playbook of triaging vulnerabilities based on CVSS scores and focusing only on "critical" issues isn't just outdated, it's recipe for disaster to strike.

In this article, we'll outline why it makes more (economic) sense to mitigate every security weakness instead of heavily relying on risk-based prioritization.

Why traditional security approaches are failing

The cybersecurity threat landscape has evolved from opportunistic attacks to sophisticated business operations. Today's threat actors are often organized criminal groups, some even state-sponsored. These aren't lone hackers anymore. They have the resources, time, and expertise to identify, catalog, and weaponize security weaknesses in SaaS companies like yours, at scale.

The commoditization of cybercrime has created an entirely new threat model. Vulnerability exploitation has become as streamlined as ordering software through an API. Criminal organizations now offer:

• Vulnerability-as-a-Service (VaaS): Pre-built exploits for specific vulnerabilities available for purchase
• Access-as-a-Service (AaaS): Direct access to compromised systems sold to the highest bidder
• Ransomware-as-a-Service (RaaS): Complete ransomware operations with 24/7 customer support

This industrialization (cybercrime-as-a-service) means that even seemingly minor vulnerabilities can be weaponized at scale, often within hours of public disclosure.

3 Reasons why every security weakness matters

1. Threats are becoming more sophisticated

Supply chain risks

It is estimated that for every 1,000 lines of code your engineering team writes, you add 10,000 lines of more code to your project. The modern SaaS application's greatest vulnerability isn't only in your code base anymore, but also in the hundreds of third-party dependencies you rely on. Supply chain attacks have increased in the past year, as attackers realize it's easier to compromise one popular package than thousands of individual applications.

"Supply chain attacks have increased in the past year, as attackers realize it's easier to compromise one popular package than thousands of individual applications."

Your "secure" application likely depends on packages that have never undergone proper security review. Consider these recent supply chain incidents that affected thousands of SaaS applications:

• Ua-parser-js malware incident: A popular npm package with 8+ million weekly downloads was compromised, injecting cryptocurrency miners and password stealers into applications worldwide
• XZ Utils backdoor incident: In 2024, a trusted contributor, Jia Tan, gradually gained maintainer access to a widely used open-source compression library integral to many Linux distributions and inserted malicious code into versions 5.6.0 and 5.6.1. The backdoor allowed remote code execution via SSH, threatening the security of countless systems across the Linux ecosystem.
• The SolarWinds breach: In 2019, attackers compromised SolarWinds’ software build environment, allowing them to inject malware into legitimate software updates. The compromised development tools affected 18,000+ organizations, demonstrating how supply chain attacks can scale exponentially.

AI-powered threats

While supply chain risks create the vulnerabilities, AI is making the exploitation process more sophisticated and accessible. AI has revolutionized social engineering attacks targeting your employees and customers:

• Personalized phishing emails: AI analyzes social media and other public data to create highly targeted phishing campaigns.
• Real-time conversation manipulation: AI chatbots can conduct convincing social engineering conversations at scale
• Deepfake voice calls: Attackers use AI to clone executive voices for fraudulent authorization requests.
• Malware development: AI is democratizing malware creation, allowing less technical attackers to develop sophisticated threats.

2. SaaS application complexity has created exponential attack surfaces

The modern SaaS application is an engineering marvel, and a security nightmare. The average SaaS application now integrates with 10 to 20 different third-party services, frameworks, and APIs. Each integration point represents a potential attack surface, and the exponential growth in complexity has made comprehensive security testing nearly impossible using traditional approaches.

The technical debt security crisis

Most SaaS companies are drowning in technical debt that directly translates to security debt. The pressure to ship features quickly has led to architectural shortcuts that accumulate vulnerabilities over time. Unlike traditional software, SaaS applications never get a "clean slate" rewrite. Instead, they evolve continuously, often built on foundations that were never designed for their current scale and complexity.

This technical debt can make seemingly (unrelated) code changes enable security weaknesses that previously have been labeled 'informative,' to become a higher severity issue. For instance, a minor update to your authentication system might expose a vulnerability in your payment processing logic that's been dormant for months.

The Integration Attack Surface Explosion

Modern SaaS applications aren't monolithic, they're complex ecosystems of interconnected services. Your "simple" project management tool likely integrates with authentication services, payment processors, email sending providers, DevOps tools, etc.

Each integration creates new attack surfaces. A weakness or security misconfiguration in any one of these services can potentially allow malicious adversaries to compromise your entire application. The interconnected nature of modern SaaS means that a security issue in one component can leveraged to access your entire (internal) system.

Microservices

The shift to microservices architecture has exponentially increased the number of potential vulnerability points. Where a monolithic application might have had 10-15 major components to secure, a microservices architecture can have 100-150 individual services, each with its own security considerations.

This can enable security weaknesses to emerge from unexpected interactions between services, creating attack vectors that are nearly impossible to identify through traditional security testing methods, and certainly not through automated means (such as SAST or DAST).

3. Unpatched weaknesses are becoming the primary breach vector

Unpatched vulnerabilities are now one of the most actively exploited attack vectors, leading directly to costly breaches and operational disruptions that can destroy SaaS businesses overnight.

The speed of modern exploitation

Recent threat intelligence reports show a dramatic increase in vulnerability exploitation as an initial attack vector in 2025, making it the second most common entry point after credential abuse. The window between disclosure and exploitation has shrunk to dangerous levels, often within hours after a new CVE has been published.

Attackers are moving with unprecedented speed, often exploiting vulnerabilities faster than security teams can even assess their impact, let alone deploy patches.

At BLACKBIRD, we can help your organisation to identify, manage and mitigate cyber risks in your SaaS application(s) up to 11.3 times faster, without getting in the way of your fast-paced SDLC. Effectively reducing your application security risk by more than 50% in a short 90-day timeframe.

This is possible thanks to our unique methodology whereby we make your SaaS application financially unattractive to threat actors. Our senior application security engineer is always ready to provide you with more information.