A vulnerability in a mobile application that many Israelis use to pay their water or other municipal bills may have left 860,000 – 1,000,000 users at risk of account takeover or theft of their personal information.
The Waterly app, by M.G.A.R. Ltd, allows users to sign up to pay their water bills. As part of the process, signing up creates an account for the user with the Pay24 service. That service allows the user to see all of their municipal bills in one account and to pay them through bill2mail. Account information may include connected data such as personal code, properties owned, contact details, and partial credit card numbers if credit card payments are made via the site.
The researchers estimate that Pay24 serves well over 1,000,000 account holders.
The vulnerability was in the bill2mail feature which was rolled out in Waterly at some date unknown to DataBreaches.net. According to “754ch1,” the independent security researcher who discovered it and who asked that we not use his real name, there was inadequate authentication of users, allowing anyone to create an account “using whatever municipal ID number they chose, with no checks in place to ensure that they were really the account owner.”
By inputting any municipal ID, the attacker – or even someone accidentally fat-fingering their ID – could gain full privileges to another’s account, “754ch1” told us:
This would potentially allow the attacker to route all victims’ municipal bills to his own desired email address. Furthermore, the breach, if abused, exposed many personal details about the victims, including their municipal bills and history of payments, debts to the city, a personal code for identification over the phone (great for social engineering), contact details and credit card details if inputted.
The vulnerability in bill2mail did not affect just the Waterly app, 754ch1 informs us, but also affected other municipal apps that are also under the MAGR umbrella.
754ch1 reported the vulnerability to CERT, who contacted MAGR. Within two weeks, the vulnerability was remediated. Once it was addressed, the report was disclosed publicly and covered on national television in Israel.
Although MAGR issued a statement affirming their commitment to privacy and security and thanking the researcher, they did not reveal whether they had found any evidence that the vulnerability had been exploited.