HospitalGown Vulnerability Exposes Apps to Backend Server Risk

Appthority reveals a link between mobile applications and publicly accessible data stores that are leaving users and their data open to attack.

Mobile App Open Port Flaws

Security vendor Appthority released new research on May 31 detailing a vulnerability it calls 'HospitalGown' which is exposing over 1,000 mobile applications to backend server risks.

The vulnerability involves improperly configured backend servers, running unsecured Elasticsearch and MySQL data stores. Appthority's analysis found 43 Terabytes of exposed data due to HospitalGown, running across over 21,000 open Elasticsearch servers.

"We discovered a huge vulnerability in mobile that we dubbed HospitalGown since it's mainly about exposed backends servers," Domingo Guerra, co-founder and president of Appthority, told eWEEK.

Appthority first began to look at the possibility of exposed server services that power mobile apps after reports emerged in December 2016 about publicly exposed MongoDB databases being attacked with ransomware. In the MongoDB security incident, hackers found publicly accessible and open database services and then encrypted them in a widespread ransomware attack.

"We decided to take a look to see how unsecured databases connect to apps and in particular apps on our enterprise users' devices," Seth Hardy, the director of security research at Appthority, told eWEEK.

Hardy said that using the dynamic analysis capabilities that Appthority does as part of its product platform, it was possible to correlate mobile apps used by enterprises to open data stores on the internet. Hardy said that the open data stores, include personally identifiable information (PII), that could expose users to risk.

The HospitalGown vulnerability is not a exploit in any given mobile application, rather it's about the data sources that mobile applications connect with to store and access information. Hardy explained that Appthority's research didn't look to see if the apps were using secure SSL/TLS transport which is another common area where mobile app security can often fail.

"It's possible that the apps were sending data over TLS, so the data would be encrypted in transit," Hardy said. "But the data was still going to an open server port that gave full read/write access without any authentication."

Hardy explained that the first step of Appthority's HosptialGown research involved using the search engine to simply look for misconfigured Elasticsearch servers that had open ports.

"We started with Shodan as the jumping off point to look for open servers and then we built on that by correlating the data with our (Appthority) dynamic analysis data," Hardy said. "We cross referenced the data sets to find the matches between what is publicly accessible on the internet and the apps on enterprise user devices."


Appthority did a deep-dive analysis on 39 mobile apps and provided vulnerability disclosure to the impacted vendors to help mitigate risks. Additionally, Appthority worked with Amazon Web Services to notify them of open Elasticsearch servers that needed to be properly configured.

"We also notified both Apple and Google for apps that are in the App Store and Google Play," Hardy said.

Both Apple and Google scan apps for potential vulnerabilities and malware prior to the apps being made publicly available to users. That said, the scanning is just for the apps themselves and typically does not include a scan of the backend services that the apps connect with.

"We (Appthority) have integrated backend server scanning into our app scanning process," Hardy said. "It's a new thing that hasn't really been considered by others before, so we're trying to lead the way there."

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.