A denial of service (DoS) occurs when software or hardware is vulnerable to crashes due to bugs or limitations in computing resources. DoS vulnerabilities do not always stem from unforeseen bugs in software, but they can occur from race conditions or functionality that returns unhandled errors. Hardware with inadequate resources could be vulnerable to a DoS when users overload it with requests. Both forms of DoS activities can cause downtime for corporations and should be avoided.
Most people have heard of a distributed denial-of-service (DDoS). A DDoS is a form of DoS where a flood of network traffic exhausts server resources and causes web services to go offline. For example, a website might not respond to the exhaustion of resources and send users a timeout error message. Timeout messages in a DDoS are caused by a large amount of traffic sent to the server from potentially thousands of devices online, usually compromised devices under a threat actor’s control. The web server does not have the resources to handle the unusually large number of requests, so the web server crashes. This type of DoS can happen to any online service open to the public.
Although DDoS is a common type of denial of service, it’s not the only way a service can be rendered non-functional. For example, race conditions often cause DoS occurrences in software. A race condition happens when one software action depends on another, but the second action can be triggered before the first. It’s a type of bug that could cause an application to crash. Race conditions can often go unnoticed until they cause downtime or affect data integrity.
DoS isn’t a condition that only affects online public systems. Internal systems can also be vulnerable to a DoS attack. Some DoS attacks are unintentional, so a DoS isn’t always a threat from a malicious person. For example, software can unintentionally cause a DoS if the target system has a race condition bug or the system is not built to deal with certain conditions or errors. A printer can go offline if it crashes from too many print requests. The crash from the printer would be considered a DoS. Users didn’t intend to perform a DoS attack, but the printer went offline due to bugs or limited resources.
In a DDoS event, businesses have no warning before the flood of traffic begins exhausting resources. For a standard DoS, businesses can have their software penetration tested. Full code reviews can help reveal DoS-related bugs such as race conditions to avoid downtime from unforeseen coding inadequacies. Malware can also be the source of a DoS, so protections from malware injection and installation on user devices are also necessary. Users can mistakenly run malware on their computers after receiving malicious links or email attachments. Malware used in DoS attacks runs silently on a user’s workstation, IoT device, or mobile smartphone and waits for the signal to flood a resource. Blocking suspicious messages helps stop malware intended for DoS attacks.
Susan Morrow
- CYBERSECURITY TERMS
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How Can TitanHQ Help?
TitanHQ helps defend against Denial of Service (DoS) attacks through:
- Email Security & Anti-Phishing Protection: Blocks phishing emails that can lead to DoS vulnerabilities.
- DNS Filtering: Prevents access to malicious sites and command-and-control servers used in DDoS attacks.
- Threat Detection: Identifies suspicious traffic patterns to catch attacks early.
Strengthen your defenses with TitanHQ’s layered security solutions.
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