When you look at the biggest cybersecurity breaches of the past decade, one thing becomes clear: the same issues keep repeating.
Insecure code, outdated dependencies, exposed secrets, misconfigured infrastructure, and unprotected sensitive data have all been exploited again and again — often with devastating consequences.
Despite billions invested in security tools, these root causes remain the Achilles’ heel of modern software. Below are five of the most well-known breaches, what went wrong, and what organizations can learn to avoid becoming the next headline.
The issue: Insecure coding practices, such as input validation flaws or unsafe object deserialization, introduce vulnerabilities that attackers can directly exploit.
The breach: In May 2021, Microsoft disclosed that attackers exploited a flaw in its Exchange Server software. The vulnerability (CVE-2021-26855) was part of a chain of insecure code patterns that enabled attackers to perform server-side request forgery (SSRF). This allowed them to gain remote access to email accounts and install web shells.
More recent case: In 2023, Atlassian’s Confluence Data Center and Server suffered a critical injection vulnerability (CVE-2023-22515). Attackers exploited a similar insecure coding flaw to gain admin privileges and exfiltrate data.
Challenge: Even well-resourced engineering teams struggle to spot subtle insecure patterns across millions of lines of code. Manual code review is not enough, and automated scans often drown teams in noise.
Why it matters: These flaws are “by design” — meaning that once they’re in production, attackers don’t need sophisticated tools to exploit them. The longer they remain, the higher the risk of mass exploitation.
The issue: Applications often rely on third-party libraries. If those libraries contain vulnerabilities, every system using them is exposed.
The breach: In 2017, Equifax suffered one of the most infamous breaches in history when attackers exploited a known vulnerability in the Apache Struts framework (CVE-2017-5638). The patch had been available for months, but was not applied.
More recent case: In late 2021, the Log4j (“Log4Shell”) vulnerability (CVE-2021-44228) shook the software world. Millions of systems worldwide used Log4j, and attackers immediately weaponized it for remote code execution. Organizations spent months auditing and patching their software.
Challenge: Modern applications depend on thousands of open-source components. Tracking, prioritizing, and patching vulnerabilities across this ecosystem is complex and time-sensitive.
Why it matters: Attackers are quick to weaponize public CVEs. A single overlooked dependency can compromise an entire organization.
The issue: Hardcoded credentials or exposed API keys in repositories give attackers direct access to sensitive systems.
The breach: In 2016, attackers found AWS credentials in a private GitHub repository used by Uber developers. They used the keys to access Uber’s AWS environment and stole personal information of 57 million customers and drivers. Uber paid attackers $100,000 in an attempt to cover up the breach, which later came to light.
More recent case: In 2022, Toyota disclosed that an access key to a database storing customer information in Japan had been exposed publicly on GitHub for five years. Around 300,000 records were at risk.
Challenge: Secrets sprawl is real. Keys and tokens often end up hardcoded, logged, or stored in insecure places. Detecting and rotating them consistently is a major operational hurdle.
Why it matters: One exposed secret is often enough for an attacker to pivot and gain control of entire systems.
The issue: Misconfigured cloud services or infrastructure leave backdoors open to attackers.
The breach: In July 2019, Capital One revealed that a misconfigured AWS S3 bucket allowed a former AWS employee to exploit a server-side request forgery (SSRF) vulnerability. The attacker accessed sensitive data stored in the cloud.
More recent case: In 2023, researchers discovered misconfigured Microsoft Azure Blob Storage instances that exposed sensitive business data from multiple companies. While not always maliciously exploited, such exposures highlight the persistence of the problem.
Challenge: Cloud environments are complex and dynamic. Simple misconfigurations can remain unnoticed until exploited. Traditional perimeter security does not protect against this.
Why it matters: Misconfigurations are consistently among the top causes of breaches in cloud-native applications. They are both common and preventable.
The issue: Storing sensitive data in plaintext or failing to enforce proper encryption exposes organizations to large-scale leaks.
The breach: In 2019, Facebook admitted that it had stored hundreds of millions of user passwords in plaintext. While no external exploitation was confirmed, the fact that employees had unnecessary access created significant risk.
More recent case: In 2022, Twitter disclosed that a bug exposed personal data of 5.4 million users, including phone numbers and email addresses, which were later sold online.
Challenge: Sensitive data needs consistent encryption, tokenization, and access control, but implementing these protections at scale is complex.
Why it matters: Once data is exposed, it cannot be taken back. Regulatory fines (like under GDPR) and customer trust damage are inevitable.
These are not new problems — yet they keep causing new breaches.
The stories above show a frustrating pattern: despite knowing these risks, organizations continue to fall victim because AppSec challenges are systemic.
Traditional tools overwhelm teams with alerts, but rarely help them fix issues in context.
This is where Glev changes the game:
Breaches like Equifax, Capital One, or Log4j don’t need to keep happening. By equipping teams with contextual, developer-friendly AppSec, Glev helps organizations build software that is secure by default — before attackers can strike.