a security weakness on usps.com that let anyone see the personal account info of its users , including usernames and street addresses . The open vulnerability was reportedly identifiedVulnerability-related.DiscoverVulnerabilityover a year ago by an independent researcher but USPS never patchedVulnerability-related.PatchVulnerabilityit until this week , when Krebs on Security flaggedVulnerability-related.DiscoverVulnerabilitythe issue . The vulnerability included all 60 million user accounts on the website . It was caused by an authentication weakness in the site ’ s application programming interface ( API ) that allowed anyone to access a USPS database offered to businesses and advertisers to track user data and packages . The API should have verified whether an account had permissions to read user data but USPS didn ’ t have such controls in place . Users ’ personal data including emails , phone numbers , mailing campaign data were all exposedAttack.Databreachto anyone who was logged into the site . Additionally , any user could request account changes for another user , so they could potentially change another account ’ s email address and phone number , although USPS does at least send a confirmation email to confirm the changes . Since street addresses are searchable through the database , any logged-in user could see who was living at each residence and even gain the data of multiple people in the same household . Krebs notes that because of the vulnerability , “ no special hacking tools were needed to pull this data. ” USPS said in a statement to Krebs : “ Any information suggesting criminals have tried to exploitVulnerability-related.DiscoverVulnerabilitypotential vulnerabilities in our network is taken very seriously . Out of an abundance of caution , the Postal Service is further investigating to ensure that anyone who may have sought to access our systems inappropriately is pursued to the fullest extent of the law. ” A recent audit of its system in October did not turn up this vulnerability , although it did find numerous other weaknesses . We ’ ve reached out for comment on whether USPS was aware of the issue when it was initially noted over a year ago . So far , no known exploits were made through this vulnerability . In USPS ’ continued efforts to modernize and adapt to the digital age , it ’ s faced numerous cybersecurity challenges .