CrowdStrike IT Outage: Incident, Response and Lesson Learned

Ahmed
16 min readAug 31, 2024

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Table of Contents:

1- Introduction

2- CrowdStrike Background

3- The Incident

4- Technical Details

5- Global Impact

6- CrowdStrike’s Response

7- Lessons Learned

8- Conclusion

1- Introduction

On July 19, 2024, a routine software update by CrowdStrike, a global leader in cybersecurity, led to one of the most significant technology outages in recent history.

Figure 1: CrowdStrike, a cybersecurity vendor facing challenges, published a root cause analysis explaining the technical issue in a software update that caused a global crash of Windows systems. (Securityweek, Aug 2024)

What was intended as a simple update to enhance the security of Windows hosts spiraled into a global crisis, crippling critical infrastructure across multiple industries. Hospitals, airports, financial institutions, and emergency services were all impacted as systems became unresponsive, leading to widespread disruptions. This incident underscores the vital importance of rigorous testing and careful deployment of software updates, particularly when they are meant to protect the very systems they ultimately destabilized. As the world becomes increasingly reliant on digital infrastructure, the CrowdStrike incident serves as a stark reminder of the potential risks involved in software management, and the cascading effects that can arise from even a single faulty update.

This article explores the details of the CrowdStrike incident, exploring its causes, the immediate and far-reaching impacts, and the lessons that can be learned to prevent such occurrences in the future.

2- CrowdStrike Background

Founded in 2011, CrowdStrike has rapidly risen to prominence as one of the world’s leading cybersecurity companies. Specializing in endpoint protection, threat intelligence, and incident response, CrowdStrike has built a reputation for offering robust solutions that safeguard organizations against increasingly sophisticated cyber threats. The company’s flagship product, the Falcon platform, is widely regarded for its advanced threat detection capabilities and has made CrowdStrike a go-to provider for enterprises seeking to protect their digital assets.

Figure 2: Some companies have reduced their forecasts as growth rates slow down. Investors have been surprised by the unexpected developments at firms like Palo Alto Networks (NASDAQ) ) and Fortinet (NASDAQ) (Yahoo Fianance, Feb 2024)

CrowdStrike’s success is reflected in its impressive market position. With a valuation exceeding $80 billion and a market share of approximately 22% in the Windows endpoint protection space, the company serves a diverse clientele that includes Fortune 500 companies, government agencies, and critical infrastructure providers. Its software is deployed across millions of devices worldwide, making it a cornerstone of cybersecurity for many businesses. Operating at the cutting edge of technology, CrowdStrike has been a pioneer in using cloud-based architectures and machine learning to enhance security. The company’s ability to detect and mitigate threats in real-time has earned it accolades within the industry and a significant customer base that relies on its solutions to protect against both known and emerging threats.

However, with great power comes great responsibility. As a leader in the cybersecurity space, CrowdStrike’s products are often integral to the operation of critical systems. This places an immense burden on the company to ensure that its software is not only effective but also reliable. The July 2024 incident highlighted the challenges and risks associated with managing such a large and influential security platform, especially when things go wrong. This background sets the stage for understanding the severity of the July 2024 software update failure, illustrating why the impact was so widespread and why the incident has sparked significant concern and scrutiny from the global tech community.

3- The Incident

On July 19, 2024, CrowdStrike released what was intended to be a routine update to its Falcon Sensor for Windows — a critical component of its endpoint protection platform. This update, however, contained a serious bug in its memory scanning feature that caused the affected Windows systems to consume 100% of a CPU core’s capacity. The result was catastrophic: systems became severely degraded in performance, with many becoming completely unresponsive.

Figure 3: Airlines experienced a global IT outage, but 72 hours later, most have largely restored their systems, with the exception of Delta Air Lines. (Growth versus , Jun 2023)

The impact was immediate and widespread. Across the globe, organizations that relied on CrowdStrike’s software experienced major disruptions. The scale of the incident was unprecedented, with an estimated 1.3 million endpoints affected. The sectors hit hardest included healthcare, aviation, finance, and emergency services — industries where uptime is critical and even minor disruptions can have serious consequences. The root cause of the incident was traced back to the memory scanning feature in the Falcon Sensor update. This bug was not caught during pre-release testing, leading to a global rollout without the usual staged deployment that would have limited its impact. The decision to bypass a phased rollout — an industry best practice — has been heavily criticized, as it allowed the faulty update to reach all Windows systems simultaneously.

CrowdStrike’s response to the incident was swift but complex. The company quickly acknowledged the problem and began working on a fix, but the nature of the issue required a manual rollback process. Affected systems had to be booted into safe mode, a specific file deleted, and then rebooted — a time-consuming procedure that had to be performed on each impacted machine individually. The fallout from this incident was significant. CrowdStrike’s stock price plummeted by 18% in the days following the event, wiping out billions of dollars in market value. The company’s reputation, previously sterling, was severely tarnished, raising questions about its quality control processes and the reliability of its software in critical environments. This incident stands as a stark reminder of the potential risks involved in software deployment, especially for systems that are integral to critical infrastructure. The global scale of the disruption caused by CrowdStrike’s update has been described as one of the largest software-induced outages in history, with long-lasting implications for the company and its clients.

4- Technical Details

The incident stemmed from a critical flaw introduced in a routine update to CrowdStrike’s Falcon Sensor for Windows. The update, which was intended to enhance the platform’s memory scanning capabilities, inadvertently introduced a bug that had disastrous consequences for systems running Windows.

Figure 4: Departure monitors at Orlando International Airport display canceled and delayed flights due to a global communications outage linked to a CrowdStrike software update on July 19, 2024. Businesses and airlines worldwide are still dealing with the impact of this global technology outage caused by CrowdStrike, a cybersecurity firm whose software is widely used across various industries. (Photo by Miguel J. Rodriguez Carrillo/Getty Images)

The primary issue was located within the Falcon Sensor’s memory scanning feature — a crucial component designed to detect and mitigate potential threats in real-time by scanning a system’s memory for malicious code. This feature, when updated, began consuming 100% of a single CPU core’s capacity on affected machines. This excessive CPU usage led to severe performance degradation, with many systems becoming completely unresponsive.

4.1. How the Bug Operated

The bug caused the memory scanning feature to enter an endless loop under specific conditions. This loop continuously consumed processing power without achieving its intended function of scanning memory for threats. As a result, systems experienced:

  • 100% CPU Utilization: One of the CPU cores was fully occupied by the faulty process, rendering the system sluggish and, in many cases, unresponsive.
  • System Instability: The overconsumption of CPU resources caused other critical processes to lag or fail, leading to frequent system crashes and blue screens (BSODs).
  • Unresponsiveness: For many users, their systems either froze or became so slow that they were effectively unusable, especially in environments where multiple high-demand applications were running concurrently.

4.2. Impact by Numbers

  • 1.3 Million Endpoints Affected: The update was deployed across approximately 1.3 million Windows endpoints globally, each experiencing varying degrees of disruption.
  • 100% CPU Core Usage: On each affected system, one CPU core was fully utilized by the faulty process, which often caused overall CPU usage to spike to critical levels, especially in systems with fewer cores.
  • Critical Service Disruption: Key sectors like healthcare and aviation reported that over 80% of their systems running CrowdStrike software were affected, leading to significant operational disruptions.

4.3. Why the Bug Wasn’t Caught

The bug slipped through CrowdStrike’s testing processes due to a combination of factors. The specific conditions that triggered the endless loop were not adequately covered in pre-release testing. The update was tested in controlled environments that did not replicate the diverse and high-demand scenarios present in real-world applications. CrowdStrike opted for a global, simultaneous deployment rather than a staged rollout, which would have involved deploying the update to a small subset of systems first. A staged rollout might have contained the issue before it affected millions of machines. The Falcon Sensor operates at the kernel level, giving it significant control over system resources. This high level of privilege meant that when the bug was triggered, it had a more profound impact on system stability and performance than it would have had if the software operated at a lower level.

4.4. CrowdStrike’s Response

Once the issue was identified, CrowdStrike issued an advisory recommending affected systems to be manually fixed. This limited the system to basic operations and prevented the faulty memory scanning feature from running. A specific file related to the memory scanning feature had to be deleted to stop the loop. After removing the problematic file, a system reboot was required to restore normal functionality. While this solution eventually resolved the issue, the process was time-consuming and had to be repeated on each affected machine individually, posing significant challenges for organizations managing large networks of devices.

5- Global Impact

The CrowdStrike incident of July 19, 2024, had far-reaching effects, causing a global technology crisis that disrupted multiple critical sectors. The faulty software update, which led to the overconsumption of CPU resources on millions of Windows systems, resulted in a cascade of failures across various industries. The scope and severity of the impact underscore the interconnectedness of modern digital infrastructure and the potential risks posed by even a single software flaw.

Figure 5: Technical outages highlight the crucial need to protect critical systems, according to the CEO of The Chertoff Group. (cnbcfm, Jul 2024)

5.1. Healthcare Sector

The healthcare sector was among the hardest hit by the incident. Hospitals, clinics, and other medical facilities worldwide experienced significant disruptions. Hospitals in North America, Europe, and Asia reported major system slowdowns, with some facilities temporarily losing access to critical patient data and medical records. The inability to access or update electronic health records (EHR) led to delays in emergency procedures. In some cases, surgeries were postponed, and critical care operations were delayed by hours, jeopardizing patient safety. Many hospitals were forced to revert to manual processes, using paper records and non-digital equipment to maintain operations. This shift increased the risk of medical errors and extended the time needed for patient care.

5.2. Aviation Sector

Airports and airlines faced widespread disruptions, leading to chaos for travelers and significant financial losses for the industry. Major international airports, including those in Sydney, London, and New York, experienced severe operational issues. Flight information display systems went down, check-in kiosks failed, and boarding processes were disrupted. The failure of airport systems led to delays and cancellations of thousands of flights globally. Sydney Airport alone saw over 200 flight delays in the first 24 hours following the incident, with passengers facing long lines and confusion due to the lack of real-time information. The aviation industry incurred substantial losses due to the disruption, with airlines facing compensation claims from passengers, operational costs, and lost revenue from canceled flights.

5.3. Financial Services Sector

The financial services industry, reliant on uninterrupted digital operations, was also significantly impacted banks across Europe, North America, and Asia experienced slowdowns in transaction processing, with some institutions reporting outages in online banking services and ATMs. The incident led to the failure of thousands of financial transactions, particularly in stock trading and foreign exchange markets. Trading platforms experienced delays and crashes, leading to market volatility and financial losses. The disruption caused widespread customer dissatisfaction, with many institutions facing financial penalties for failing to meet service level agreements (SLAs).

5.4. Emergency Services

The impact on emergency services was particularly concerning, as it directly affected public safety. Police, fire, and ambulance services in several regions reported failures in their dispatch systems, leading to delays in response times and coordination challenges during emergencies. Communication systems used by emergency responders were also impacted, leading to instances where first responders were unable to communicate effectively during critical operations.

5.5. Global Economic Impact

The cumulative effect of the disruptions across these sectors had a notable impact on the global economy. The widespread nature of the disruptions, particularly in essential services like healthcare and financial services, contributed to an estimated $2 billion hit to global GDP. The economic impact was felt in both direct costs, such as lost revenue and operational expenses, and indirect costs, including decreased productivity and consumer confidence. Following the incident, CrowdStrike’s stock price dropped by 18%, resulting in a loss of billions of dollars in market value. The incident also caused temporary volatility in tech stocks and companies reliant on CrowdStrike’s services.

5.6. Long-Term Consequences

The global impact of the CrowdStrike incident will likely have long-term consequences for the company and the industries affected. CrowdStrike’s reputation as a leader in cybersecurity has been severely tarnished. Customers may seek alternative solutions, particularly in sectors where system reliability is critical. The incident has drawn the attention of regulators, particularly in the United States and European Union, who are likely to impose stricter regulations and oversight on software updates for critical infrastructure. Organizations worldwide are reevaluating their cybersecurity strategies, with an increased focus on resilience, redundancy, and the use of phased rollouts for critical updates. The CrowdStrike incident serves as a powerful reminder of the potential global consequences of software failures in our increasingly interconnected world. The event highlights the need for robust testing, careful deployment, and contingency planning to mitigate the risks associated with digital infrastructure.

6. CrowdStrike’s Response

Immediately after reports of system failures began to surface, CrowdStrike acknowledged the problem and launched an investigation. The company quickly identified the faulty memory scanning feature in its Falcon Sensor for Windows as the root cause of the disruption. Within hours, CrowdStrike issued a public statement outlining the issue and began communicating with affected customers.

CrowdStrike released multiple public statements through its website, social media channels, and direct communications with clients, providing updates on the situation. The company’s CEO, George Kurtz, personally addressed the incident, emphasizing the company’s commitment to resolving the issue and supporting its customers. To manage the influx of support requests, CrowdStrike expanded its customer support operations, deploying additional technical staff and setting up dedicated support hotlines. The company also provided detailed instructions for troubleshooting and manually fixing affected systems.

6.1. Issuing a Fix

The first priority for CrowdStrike was to stop the faulty update from causing further damage. To this end, the company immediately halted the distribution of the faulty update and began rolling back the changes. For unaffected systems, the rollback prevented the bug from spreading further. For systems that were already impacted, CrowdStrike developed a manual fix. This process involved booting the affected systems into Safe Mode, manually deleting the problematic file, and then rebooting the systems to restore functionality. Detailed step-by-step instructions were provided to customers, and CrowdStrike support teams assisted in implementing these fixes across large networks.

However, the manual nature of the fix proved to be a significant challenge:

a. Each affected machine required individual attention, making the process time-consuming, especially for organizations with thousands of endpoints. The fix could take several hours per machine, depending on the severity of the impact and the complexity of the network.

b. Large enterprises and critical infrastructure providers had to dedicate substantial resources to apply the fix, often diverting IT staff from other critical tasks. This not only delayed the overall recovery but also led to significant operational disruptions.

6.2. Post-Incident Measures

In the aftermath of the incident, CrowdStrike committed to a thorough review of its internal processes and made several key changes to prevent similar occurrences in the future. CrowdStrike pledged to strengthen its pre-release testing protocols, particularly for updates to critical features like memory scanning. The company also introduced additional layers of testing, including expanded simulations of real-world environments to better detect potential issues before updates are deployed. Acknowledging the failure to implement a staged rollout, CrowdStrike revamped its deployment strategy to include mandatory canary releases — a process where updates are first deployed to a small subset of users to identify potential issues before a full-scale release. This approach is designed to catch bugs like the one that caused the July 19 incident before they can affect a large number of systems. To rebuild trust, CrowdStrike adopted a policy of greater transparency, committing to more open communication with customers and stakeholders about updates, potential risks, and the steps being taken to mitigate them. The company also established an independent review board to oversee its software development and deployment practices.

6.3. Market and Regulatory Impact

Despite the swift response, the incident had a lasting impact on CrowdStrike’s market position and triggered increased scrutiny from regulators. Following the incident, CrowdStrike’s stock price dropped by 18%, erasing billions of dollars in market value. The recovery of the stock was slow, reflecting ongoing concerns among investors about the company’s operational risks. Regulatory bodies, particularly in the United States and the European Union, launched investigations into the incident. These investigations focused on CrowdStrike’s software deployment practices and the broader implications for critical infrastructure security. The company is likely to face stricter regulations and oversight in the future as a result.

CrowdStrike’s response to the incident, while effective in many respects, highlighted the challenges of managing large-scale software deployments in critical environments. The lessons learned from this incident have not only shaped CrowdStrike’s future strategies but also served as a wake-up call for the broader cybersecurity industry about the importance of rigorous testing, phased deployments, and proactive customer communication.

7. Lessons Learned

The July 19, 2024, CrowdStrike incident serves as a pivotal case study in the importance of robust software deployment practices and the critical need for meticulous testing, especially when dealing with systems that underpin vital infrastructure. The fallout from the incident offers several key lessons for both CrowdStrike and the wider technology industry.

Figure 6: A Times Square Crowdstrike blue screen of death ‘BSOD’ (Joke_Mummy Reddit, Jult 2024)

A method to resolve CrowdStrike bug:

  1. Enter Troubleshooting mode from Boot.
  2. Open a command prompt.
  3. Navigate to C:\Windows\System32\drivers\CrowdStrike.
  4. Find “C-00000291* sys” and delete it or Rename CSAgent.sys (i.e. donotcrash.sys.).
  5. Proceed with a restart.

7.1. The Necessity of Staged Rollouts

One of the most significant oversights in the CrowdStrike incident was the decision to bypass a staged rollout for the update. A staged rollout, where updates are deployed incrementally to a small subset of users before a full-scale release, is a best practice that allows developers to identify and fix potential issues before they affect all users. Had CrowdStrike employed a staged rollout or canary release strategy, the memory scanning bug might have been detected early, limiting the impact to a small number of systems rather than the approximately 1.3 million endpoints that were affected globally. Following the incident, there has been a broader industry push towards adopting staged rollouts as a standard practice, particularly in sectors where software stability is crucial. Companies are now increasingly aware that even minor updates can have catastrophic consequences if not properly vetted in real-world environments.

7.2. Comprehensive Testing is Crucial

The incident highlighted deficiencies in CrowdStrike’s pre-release testing processes. The memory scanning feature, which caused the outage, was not adequately tested under the diverse conditions found in real-world environments, leading to its failure when deployed. Post-incident, CrowdStrike has expanded its test coverage to include a wider range of scenarios, particularly those involving high-load environments that more accurately reflect the conditions in critical infrastructure systems. This includes simulations of various operating system configurations, workloads, and network conditions. The incident underscored the need for a balanced approach that integrates both automated testing and manual, scenario-based testing. Automated tests can identify basic functionality issues, but manual testing in realistic scenarios is necessary to catch more complex bugs like the one that led to this outage.

7.3. The Risks of High-Privilege Software

CrowdStrike’s software operates at the kernel level, giving it significant control over system resources. While this level of access is necessary for effective endpoint protection, it also means that any bug in the software can have a disproportionate impact on system stability. The incident has prompted a reevaluation of how high-privilege software is developed and tested. Companies are now more focused on ensuring that such software is not only secure but also stable and failsafe, with mechanisms in place to prevent it from compromising system performance in the event of an issue.

7.4. Importance of Clear and Timely Communication

CrowdStrike’s response to the incident included efforts to communicate with affected customers, but the complexity of the issue and the manual nature of the fix meant that many organizations were left struggling to restore normal operations. The incident has led to the development of more comprehensive crisis communication protocols within the industry. These protocols emphasize the importance of clear, timely, and consistent communication to keep customers informed about the nature of the problem, the steps being taken to resolve it, and what customers need to do on their end.

7.5. Economic and Reputational Impact

The economic and reputational fallout from the incident was significant. CrowdStrike’s stock price dropped by 18%, and the company faced potential losses in customer trust and market share. The incident has reinforced the financial risks associated with software failures, particularly for companies providing critical infrastructure services. It is estimated that the global economic impact of the outage could reach up to $2 billion, considering the disruptions across various sectors, including healthcare, aviation, and finance.

7.6. Regulatory Implications

The widespread impact of the CrowdStrike incident attracted regulatory scrutiny, particularly concerning the deployment practices for software used in critical infrastructure. In the aftermath, regulators in the United States and European Union are expected to impose stricter guidelines and oversight on the deployment of software updates, especially for companies operating in sectors that involve critical infrastructure. These regulations can include mandatory staging of updates, enhanced testing requirements, and more rigorous reporting obligations in the event of an incident.

8. Conclusion

The CrowdStrike incident on July 19, 2024, stands as one of the most significant software-induced outages in recent history, with widespread implications across multiple critical sectors. The incident, caused by a faulty update to the Falcon Sensor for Windows, affected approximately 1.3 million endpoints worldwide, leading to severe disruptions in healthcare, aviation, financial services, and emergency operations. The global economic impact of the outage is estimated to have reached up to $2 billion, reflecting both direct operational losses and broader effects on productivity and consumer confidence. CrowdStrike’s swift response, including rolling back the update and providing a manual fix, helped to mitigate further damage, but the challenges associated with recovering from such a widespread outage highlighted the limitations of even the most well-intentioned crisis management efforts. The company’s stock price fell by 18% in the immediate aftermath, erasing billions of dollars in market value and prompting a reassessment of its operational and deployment practices.

This incident has sparked a broader conversation within

· The technology industry about the importance of rigorous testing, phased rollouts, and transparent communication.

· The need for companies operating in critical infrastructure sectors to prioritize stability and reliability in their software deployments, recognizing that even minor oversights can have catastrophic consequences when scaled globally.

· Influence industry standards and regulatory frameworks, particularly in regions like the United States and the European Union, where the impact was most keenly felt.

Companies are expected to adopt more cautious and methodical approaches to software updates, incorporating best practices such as canary releases and comprehensive real-world testing to safeguard against similar incidents. For CrowdStrike, the road to recovery involves not only addressing the technical flaws that led to the outage but also rebuilding trust with its customers and stakeholders. The company’s commitment to enhancing its testing protocols, adopting staged rollouts, and improving crisis communication will be crucial in restoring its reputation as a leader in cybersecurity. As the digital world becomes increasingly complex and interconnected, the CrowdStrike incident serves as a powerful reminder of the critical importance of software reliability, particularly in systems that support essential services and infrastructure.

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Ahmed
Ahmed

Written by Ahmed

I am interested in Data Science | Security Research | Cloud Computing https://mawgoud.medium.com/subscribe

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