Fresh on the heels of a disclosure that Microsoft Corp. leaked internal customer support data to the Internet, mobile provider Sprint has addressed a mix-up in which posts to a private customer support community were exposed to the Web.

KrebsOnSecurity recently contacted Sprint to let the company know that an internal customer support forum called “Social Care” was being indexed by search engines, and that several months worth of postings about customer complaints and other issues were viewable without authentication to anyone with a Web browser.

A Sprint spokesperson responded that the forum was indeed intended to be a private section of its support community, but that an error caused the section to become public.

“These conversations include minimal customer information and are used for frontline reps to escalate issues to managers,” said Lisa Belot, Sprint’s communications manager.

A review of the exposed support forum by this author suggests that while none of the posts exposed customer information such as payment card data, a number of them did include customer account information, such customer names, device identifiers and in some cases location information.

Perhaps more importantly for Sprint and its customers, the forum also included numerous links and references to internal tools and procedures. This sort of information would no doubt be of interest to scammers seeking to conduct social engineering attacks against Sprint employees as way to perpetrate other types of fraud, including unauthorized SIM swaps or in gleaning more account information from targeted customers.

Earlier this week, vice.com reported that hackers are phishing workers at major U.S. telecommunications companies to gain access to internal company tools. That news followed a related Vice report earlier this month which found ne’er-do-wells are now getting telecom employees to run software that lets the hackers directly reach into the internal systems of U.S. telecom companies to take over customer cell phone numbers.

The misstep by Sprint comes just days after Microsoft acknowledged that a database containing “a subset of information related to customer support interactions was accessible to the internet between the dates of Dec. 5 and Dec. 31, 2019.” Microsoft said it was alerting individuals whose information was exposed, which included location information, email and IP addresses, telephone numbers and descriptions of technical issues.

This week marked the annual observance of Data Privacy Day, an occasion in which we are reminded to be more judicious about the types of personal information we voluntarily share on social media and other Web sites. But both the Microsoft and Sprint stumbles are a reminder that billion-dollar companies very often expose this information on our behalf, even when we are doing everything within our power to safeguard it.