he foundVulnerability-related.DiscoverVulnerability76 iOS apps that are vulnerableVulnerability-related.DiscoverVulnerabilityto an attack that can intercept protected data . TLS is used to secure an app ’ s communication over an internet connection . Without it , a hacker can essentially eavesdrop over a network to spy on whatever data the app sends , such as login information . “ This sort of attack can be conducted by any party within Wi-Fi range of your device while it is in use , ” Strafach said . “ This can be anywhere in public , or even within your home if an attacker can get within close range ” . Strafach discoveredVulnerability-related.DiscoverVulnerabilitythe vulnerability in the 76 apps by scanning them with his company-developed security service , verify.ly , which he 's promoting . It flagged “ hundreds of applications ” with a high likelihood of data interception . He ’ s so far confirmedVulnerability-related.DiscoverVulnerabilitythat these 76 apps possess the vulnerability . He did so by running them on an iPhone running iOS 10 and using a proxy to insert an invalid TLS certificate into the connection . Strafach declaredVulnerability-related.DiscoverVulnerabilitythat 43 of the apps were either a high or medium risk , because they risked exposing login information and authentication tokens . Some of them are from “ banks , medical providers , and other developers of sensitive applications , ” he said . He 's not disclosingVulnerability-related.DiscoverVulnerabilitytheir names , to give them time to patchVulnerability-related.PatchVulnerabilitythe problem . The remaining 33 apps were deemed low risks because they revealed only partially sensitive data , such as email addresses . They include the free messaging service ooVoo , video uploaders to Snapchat and lesser-known music streaming services , among many others . In all , the 76 apps have 18 million downloads , according to app market tracker Apptopia , Strafach said . It ’ ll be up to the app developers to fixVulnerability-related.PatchVulnerabilitythe problem , but it only involves changing a few lines of code , says Strafach , who ’ s been trying to contact the developers . He included some warnings for developers in the blog post . “ Be extremely careful when inserting network-related code and changing application behaviors , ” he wrote . “ Many issues like this arise from an application developer not fully understanding the code they ’ ve borrowed from the web ” . Users of affected apps can protect themselves by turning off the Wi-Fi when in a public location , Strafach says . That will force the phone to use a cellular connection to the internet , making it much harder for any hacker to eavesdrop unless they use expensive and illegal equipment , Strafach said