COMMENTARY: Managed security services providers (MSSPs) and managed services providers (MSPs) occupy a unique and trusted position in the supply chain, which makes them high-value targets for cybercriminals and nation-state hackers. By compromising one MSSP or MSP, a threat actor can access many client organizations at once, an efficiency that attackers find irresistible. In the case of the recent CentreStack breach, an MSP’s compromised file-sharing portal can potentially expose numerous companies’ confidential files or provide direct pathways into those companies’ internal systems. That risk is what we’re unpacking in light of this breach.
Similarly, if an MSSP is compromised, the attacker might gain the ability to disable security monitoring or deliver malware across multiple businesses that trusted that MSSP for protection. Historically, threat actors have deliberately targeted service providers to maximize impact. For example, the notorious Kaseya VSA attack in 2021 demonstrated how one compromised product used by numerous MSPs created a cascading effect, leaving many organizations infected and their data held for ransom. In that incident, ransomware spread through an MSP’s remote management software to hundreds of downstream customers.
These examples underline a reality for MSPs and MSSPs: Threat actors see providers as one-stop shops for breaching multiple targets in one go. The very tools and access that enable MSSPs and MSPs to efficiently support clients (remote admin portals, monitoring agents, shared cloud platforms, etc.) can be turned against them if compromised. This puts the MSSP or MSP at risk, as well as every business that relies on that provider’s services. From a business perspective, an attack on an MSP or MSSP can be devastating to trust and reputation. Clients assume their service providers will enhance security, not become a liability. When attackers target MSSPs and MSPs, they are exploiting the implicit trust between providers and customers, often using the service provider’s legitimate access to slip past clients’ defenses. This “trusted access” amplifies the damage of any single vulnerability or breach in an MSSP or MSP environment, making service providers an ideal vehicle for large-scale attacks that can simultaneously victimize many organizations.
How vulnerabilities cascade from service providers to customers
When a vulnerability like CVE-2025-30406 is weaponized against an MSP, the consequences can cascade across that MSSP's or MSP’s entire client base. In a worst-case scenario, a single successful exploit leads to a chain reaction of compromises. An attacker who achieves RCE on an MSSP's or MSP’s CentreStack server could, for instance, access sensitive files for multiple end-customer companies at once, steal data in bulk or deploy ransomware across all tenant shares simultaneously. The Gladinet CentreStack platform is explicitly designed for multi-tenancy (allowing one deployment to serve many clients), which means an RCE exploit jeopardizes every tenant hosted on that instance. Thus, what begins as one server breach can quickly escalate into a multi-organization data breach or outage.
Both technical and non-technical stakeholders should recognize this “kill many birds with one stone” effect. Security experts often warn that a vulnerable MSSP or MSP can be an initial access vector to numerous victim networks, with globally cascading effects. In practice, that could mean dozens of hospitals, banks, law firms, or retailers (all clients of the same service provider) simultaneously losing access to critical data or seeing their systems encrypted by ransomware. Indeed, officials note that compromising an MSSP or MSP enables follow-on attacks – such as ransomware or espionage- not just against the provider but across the MSSP's or MSP’s customer base. This ripple effect dramatically amplifies the scale of any single vulnerability. A business that might otherwise consider a “single-server” issue low priority must realize that in an MSSP or MSP context, one server’s compromise can knock out services for many companies at once.
The financial losses, legal liabilities, and brand damage multiply in a cascading breach: The MSP faces a possible breach of contract and erosion of client confidence, while each of its affected customers suffers downtime and incident response costs of their own. From a risk management viewpoint, such vulnerabilities blur the line between an incident at the provider and incidents at each customer. Regulators and industry groups increasingly emphasize supply-chain security and “downstream risk” for this reason. In essence, MSP and MSSP vulnerabilities create a domino effect, turning what would be a single-company attack into a sector-wide event. This is why cascading attacks on service providers are considered so dangerous; they can rapidly impact a large swath of the economy, and they can be challenging to contain once they start.
Key takeaways for MSPs/MSSPs and their customers
Companies impacted by the CentreStack breach are experiencing the following in real time. However, all MSPs and MSSPs should review their security strategy to ensure it accounts for the unique position they are in as service providers.
Learning from the cautionary tale
By understanding the gravity of MSSP- and MSP-focused vulnerabilities and responding decisively, service providers can protect their own operations and shield their customers from cascading cyber threats. The Gladinet CentreStack incident is a cautionary tale that will hopefully encourage all MSPs and MSSPs to double down on security best practices, continuous monitoring, and rapid incident response in the face of emerging threats. In the MSSP/MSP world, security holes in one platform can quickly become everyone’s problem, so proactive defense and quick patch management are absolutely important.
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