In the ever-evolving landscape of cybersecurity, it’s easy to become fixated on emerging threats, often overlooking legacy vulnerabilities that persist within our systems. Recent trends indicate a notable resurgence of classic attack vectors, such as SQL injections, buffer overflows, and web shells—techniques that many assumed had been relegated to the annals of cyber history. This revival prompts a re-examination of our current defensive postures and underscores the necessity of maintaining vigilance against both new and established threats.
While with SQLi we are ultimately targeting a database, what we are really looking for is where the complexity and human elements of a system have exposed a vulnerability.
The Revival of SQL Injection Attacks
SQL injection (SQLi) remains one of the most prevalent and damaging forms of cyber-attack. This technique involves inserting malicious SQL code into input fields, enabling attackers to access, modify, or delete data within a database. Despite being a well-documented vulnerability with known mitigation strategies dating as far back as the late 1990s (yes, that’s close to 30 years ago), SQLi continues to pose significant risks. For example, in 2024, SQL injections were identified as the most common high and critical vulnerability in sectors such as media and healthcare industries.
A notable incident underscoring the persistence of SQLi vulnerabilities occurred in early 2025, when a critical SQL injection flaw (CVE-2025-1094) was discovered in PostgreSQL’s interactive terminal, psql. This vulnerability allowed attackers to execute arbitrary SQL commands, potentially compromising sensitive data. The existence of such a flaw in a widely used database system highlights the ongoing challenges in securing applications against SQL injection attacks.
According to Offensive Security Consultant, Chris Carlis, “As an attacker, we hunt for weaknesses in the gaps where different technologies interact, where diverse developers need to coordinate, and different teams manage operations. While with SQLi we are ultimately targeting a database, what we are really looking for is where the complexity and human elements of a system have exposed a vulnerability. The relatively low effort, high impact results of a SQLi exploit has helped it to remain an evergreen vulnerability class for us.”
Buffer Overflow Vulnerabilities: An Old Foe Returns
Buffer overflow vulnerabilities, where a program writes more data to a buffer than it can hold, have been known for decades, with the first being documented in 1988 and popularized in the 1996 Phrack.org article, “Smashing the Stack for Fun and Profit”. These vulnerabilities can lead to system crashes, data corruption, or arbitrary code execution by attackers. Despite advancements in programming practices and security measures, buffer overflows remain a significant concern. In February 2025, the Cybersecurity and Infrastructure Security Agency (CISA) and the Federal Bureau of Investigation (FBI) issued a joint alert warning about malicious actors exploiting buffer overflow vulnerabilities to compromise software. The alert emphasized the need for adopting secure-by-design principles and utilizing memory-safe programming languages to mitigate such risks.
Web Shells: They are Still Nasty
Web shells are malicious scripts uploaded to web servers, providing attackers with remote access and control over the compromised systems. They serve as backdoors, enabling unauthorized operations such as data theft, server manipulation, and launching further attacks. Web shells can be written in various programming languages, including PHP, ASP, and Python, making them versatile tools for cybercriminals. In 2024, over 12% of hacked websites cleaned by post breach restoration firms had at least one web shell present, underscoring the prevalence of this threat.
Why Are Old Attack Vectors Resurfacing?
The resurgence of these classic attack vectors can be attributed to several factors:
- Assumed Obsolescence: Many organizations consider these vulnerabilities as problems of the past, leading to complacency in monitoring and defending against them.
- Focus on Emerging Threats: The cybersecurity community often concentrates on new and sophisticated threats, such as Business Email Compromise (BEC) and ransomware, potentially neglecting older vulnerabilities.
- Legacy Systems: Numerous organizations continue to operate legacy systems (no kidding – recently worked a case with Windows XP and 2000 systems) with outdated software that may lack patches for known vulnerabilities, making them susceptible to classic attack methods.
- Attackers’ Adaptability: Cybercriminals are continuously evolving their tactics. Revisiting older attack vectors that are no longer top-of-mind for defenders can be an effective strategy to exploit unpatched or poorly defended systems.
While defenders implement new security measures, attackers often revert to time-tested techniques that exploit overlooked vulnerabilities...
The Unchanging Nature of Cyber Threats
Despite technological advancements, the fundamental dynamics of cyber threats have remained consistent over the years. The cat-and-mouse game between attackers and defenders continues, with each side adapting to the other’s strategies. While defenders implement new security measures, attackers often revert to time-tested techniques that exploit overlooked vulnerabilities…and so on, and so on and so on…
In 2024, cyberattacks surged globally, with organizations experiencing an average of 1,876 attacks per week in the third quarter—a 75% increase from the same period in 2023. This escalation illustrates the relentless nature of cyber threats and the necessity for organizations to maintain robust and comprehensive security postures.
The Cost of Complacency
The financial implications of cyberattacks are truly staggering. In 2024, the global average cost of a data breach reached $4.88 million, marking a 10% increase over the previous year and the highest total ever recorded. Breaches not only produce immediate financial losses but can also cause long-term reputational damage and operational disruptions.
For instance, in 2024, Halliburton, a prominent oilfield-services company, suffered a cyberattack that led to certain systems being taken offline as a protective measure. The breach prompted an internal investigation and highlighted the vulnerabilities even large organizations face.
The Imperative for Comprehensive Security Strategies
To effectively combat both emerging and resurging threats, organizations must adopt comprehensive security strategies that encompass:
- Continuous Monitoring: Implementing real-time monitoring systems to detect and respond to unusual activities indicative of both new and traditional attack vectors.
- Regular Patching: Ensuring that all systems, including legacy applications, are up-to-date with the latest security patches to mitigate known vulnerabilities.
- Security Training: Educating employees about the full spectrum of cyber threats, emphasizing that older attack methods remain relevant and dangerous.
- Adoption of Secure Coding Practices: Encouraging the use of memory-safe programming languages and secure-by-design principles during software development to prevent vulnerabilities like buffer overflows.
- Operational Readiness: Strengthening your organization’s incident response capabilities by engaging in Tabletop Exercises (TTX) designed to simulate real-world cyber threats. These exercises help teams develop critical decision-making skills, improve coordination, and build the muscle memory necessary to respond swiftly and effectively to cyber incidents.
The resurgence of older attack vectors like SQL injections, buffer overflows, and web shells serves as a stark reminder that cybersecurity is not just about defending against the latest and greatest threats but also maintaining vigilance against time-tested exploits. While defenders tend to focus on emerging dangers such as BECs and ransomware, attackers are leveraging forgotten vulnerabilities.
The increase in cyberattacks, coupled with rising breach costs, highlights the importance of a comprehensive cybersecurity strategy that includes continuous monitoring, regular patching, secure coding practices, and ongoing security awareness training. Cybercriminals remain adaptive and persistent, unconstrained by corporate priorities such as timesheets, KPIs or quarterly earnings targets. If organizations fail to recognize that old threats never truly disappear, they risk falling victim to the very vulnerabilities they assumed were no longer relevant. Staying ahead in this endless cat-and-mouse game requires a mindset that respects the past while preparing for the future. 
Chris Pogue
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