Incident: Outlook.com Service Outage Caused by Expired SSL Certificate

Published Date: 2013-02-25

Postmortem Analysis
Timeline 1. The software failure incident with Microsoft's Outlook.com occurred three days after the software company suffered an embarrassing outage to its Windows Azure storage service, caused by an expired security certificate [17204]. 2. Published on 2013-02-25 08:00:00+00:00. 3. The software failure incident with Microsoft's Outlook.com occurred around February 22, 2013.
System 1. Outlook.com 2. Windows Azure storage service
Responsible Organization 1. The software failure incident affecting Outlook.com was caused by an expired security certificate for Microsoft's Windows Azure storage service, leading to a global meltdown [17204].
Impacted Organization 1. Outlook.com users [17204] 2. Connected Services for adding or editing Twitter connections [17204] 3. Business and education users of Office 365 [17204]
Software Causes 1. Expired SSL certificate for Windows Azure storage service [17204]
Non-software Causes 1. The Outlook.com service downtime was caused by an expired security certificate for Microsoft's Windows Azure storage service, which led to a global meltdown [17204].
Impacts 1. Outlook.com, Microsoft's consumer Web-based e-mail service, experienced downtime for some users, impacting their ability to access and use the email service [17204]. 2. Connected Services were impacted, preventing customers from adding or editing their Twitter connections through their Microsoft Account [17204]. 3. The outage affected tens of millions of Outlook.com users, causing inconvenience and disruption to their email communication [17204]. 4. The software failure incident also had implications for other Microsoft cloud-based services, such as business and education users of Office 365, due to the expired SSL certificate affecting Azure services [17204].
Preventions 1. Regularly monitoring and renewing SSL certificates to prevent expiration-related outages like the one experienced by Microsoft Azure [17204]. 2. Implementing robust monitoring systems to quickly detect and address any issues that may arise with the service, such as the Outlook.com downtime, to minimize user impact [17204]. 3. Conducting thorough testing and quality assurance processes before deploying updates or changes to the software to prevent unexpected issues that could lead to service disruptions [17204].
Fixes 1. Renewing the expired SSL certificate that caused the outage on the Windows Azure storage service, as mentioned in [17204]. 2. Identifying and resolving the root cause of the issue causing the downtime of Outlook.com, as acknowledged by Microsoft but not detailed in [17204]. 3. Restoring the affected services and connections for Outlook.com users, such as the ability to add or edit Twitter connections, as mentioned in [17204].
References 1. Twitter posts by @MicrosoftHelps [17204] 2. Microsoft's service status page [17204] 3. ZDNet's Mary Jo Foley [17204]

Software Taxonomy of Faults

Category Option Rationale
Recurring one_organization (a) The software failure incident having happened again at one_organization: - Microsoft experienced an embarrassing outage to its Windows Azure storage service caused by an expired security certificate just three days before the Outlook.com downtime incident [17204]. (b) The software failure incident having happened again at multiple_organization: - There is no specific mention in the provided article about similar incidents happening at other organizations or with their products and services.
Phase (Design/Operation) design, operation (a) The software failure incident related to the design phase is evident in the article as Microsoft experienced an embarrassing outage to its Windows Azure storage service due to an expired security certificate. The SSL certificate, used to securely authenticate the service, expired, causing a complete global meltdown of Azure services [17204]. (b) The software failure incident related to the operation phase is seen in the article as Microsoft's consumer Web-based e-mail service, Outlook.com, experienced downtime for some users. The issue impacted Connected Services, specifically affecting customers' ability to add or edit their Twitter connections while trying to connect their Microsoft Account to Twitter [17204].
Boundary (Internal/External) within_system (a) within_system: The software failure incident related to Outlook.com being down was within the system. Microsoft confirmed the issue with its consumer Web-based e-mail service but did not detail the exact cause of the downtime. The outage was not suspected to be due to hacking. Additionally, the article mentions a previous embarrassing outage to Microsoft's Windows Azure storage service caused by an expired security certificate, which was an internal issue within the system [17204].
Nature (Human/Non-human) non-human_actions (a) The software failure incident related to non-human actions: - The outage of Microsoft's consumer Web-based e-mail service, Outlook.com, was caused by an expired security certificate for the Windows Azure storage service [17204]. - The SSL certificate used to authenticate the service expired, leading to a complete global meltdown of Azure and affecting various Microsoft cloud-based services [17204]. (b) The software failure incident related to human actions: - The article does not mention any contributing factors introduced by human actions that led to the software failure incident.
Dimension (Hardware/Software) hardware, software (a) The software failure incident related to hardware: - The article mentions an incident where Microsoft's Windows Azure storage service suffered an outage due to an expired security certificate, which is a hardware-related issue [17204]. (b) The software failure incident related to software: - The article reports that Microsoft's consumer Web-based e-mail service, Outlook.com, experienced downtime, but it was not suspected to be due to hacking. This indicates a software-related issue [17204].
Objective (Malicious/Non-malicious) non-malicious (a) The software failure incident related to the Outlook.com outage was non-malicious. Microsoft confirmed that the issue was not due to hacking, indicating that there was no malicious intent behind the downtime [17204].
Intent (Poor/Accidental Decisions) accidental_decisions (a) The software failure incident related to the Outlook.com downtime and the Azure storage service outage was not due to poor decisions but rather an expired security certificate. The outage was caused by the SSL certificate used for authentication expiring, leading to a global meltdown of Azure services [17204].
Capability (Incompetence/Accidental) accidental (a) The software failure incident related to development incompetence is not explicitly mentioned in the provided article [17204]. (b) The software failure incident related to an accidental factor is evident in the article [17204] where Microsoft experienced an embarrassing outage to its Windows Azure storage service due to an expired security certificate. The outage was caused by the SSL certificate expiring, which was not intentional but accidental.
Duration temporary (a) The software failure incident related to Outlook.com being down was temporary. Microsoft confirmed the issue and mentioned they were aware of it but did not detail the cause or how long it would take to restore services [17204]. Additionally, the article mentioned that the outage ended after a new certificate was installed for the Azure service, indicating a temporary nature of the failure [17204].
Behaviour crash (a) crash: The article mentions that Microsoft's consumer Web-based e-mail service, Outlook.com, was down for some people, indicating a crash where the system lost its state and was not performing its intended functions [17204]. (b) omission: The article does not specifically mention any instances of the system omitting to perform its intended functions at an instance(s). (c) timing: The article does not indicate any issues related to the system performing its intended functions too late or too early. (d) value: The article does not mention any instances of the system performing its intended functions incorrectly. (e) byzantine: The article does not describe any inconsistent responses or interactions by the system. (f) other: The behavior of the software failure incident in this case is primarily a crash, where the system was down and not performing its intended functions for some users [17204].

IoT System Layer

Layer Option Rationale
Perception None None
Communication None None
Application None None

Other Details

Category Option Rationale
Consequence unknown (a) death: People lost their lives due to the software failure (b) harm: People were physically harmed due to the software failure (c) basic: People's access to food or shelter was impacted because of the software failure (d) property: People's material goods, money, or data was impacted due to the software failure (e) delay: People had to postpone an activity due to the software failure (f) non-human: Non-human entities were impacted due to the software failure (g) no_consequence: There were no real observed consequences of the software failure (h) theoretical_consequence: There were potential consequences discussed of the software failure that did not occur (i) other: Was there consequence(s) of the software failure not described in the (a to h) options? What is the other consequence(s)? The articles do not mention any consequences such as death, harm, basic needs impact, property loss, or non-human entities being affected due to the software failure incident. The main consequence discussed is the service outage and inconvenience caused to users of Outlook.com and other Microsoft cloud-based services like Office 365 [17204].
Domain information, finance (a) The software failure incident mentioned in the articles is related to the information industry. Microsoft's consumer Web-based e-mail service, Outlook.com, experienced downtime, impacting users' ability to access and communicate through their email accounts [17204]. Additionally, the outage affected Connected Services, such as the ability to add or edit Twitter connections, highlighting the disruption in information exchange [17204]. (h) The software failure incident also has implications for the finance industry. The outage of Outlook.com, a widely used email service, could have affected users who rely on email communication for financial transactions, notifications, and other financial-related activities [17204]. (m) The software failure incident is not directly related to any other specific industry mentioned in the options provided.

Sources

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