Facebook’s Android app uses two methods of downloading files from a group — a built-in Android service called DownloadManager and a second method called Files Tab.
Security researcher Sayed Abdelhafiz discovered a path traversal flaw in the second method.
“I discovered an ACE on Facebook for Android that can be triaged through a download file from group Files Tab without opening the file,” he said in a post on Medium.
The vulnerability was in the second method. While security measures were implemented on the server side when uploading the files, it was easy to bypass those.
“First idea that came to my mind was to use path traversal to overwrite native libraries which will lead to executing arbitrary code,” Abdelhafiz said.
Abdelhafiz explained how the Files Tab flaw enabled the researcher to launch RCE attacks against a target device.
The vulnerability in the Files Tab has now been fixed.
In June this year, Ahmedabad-based security researcher Bipin Jitiya won Rs 23.8 lakh ($31,500) from Facebook for identifying a bug in its social networking platform and a third-party business intelligence portal.
Jitiya, 26, identified the web security vulnerability in internal blind Server-Side Request Forgery (SSRF) in the source code of a publicly accessible endpoint, built using tools from MicroStrategy, that performed custom data collection and content generation.
MicroStrategy has partnered with Facebook on data analytics projects for several years. Jitiya reported the bug to the MicroStrategy’s security team, who acknowledged it, saying the issue has been mitigated.
In May, a 27-year-old Indian security researcher Bhavuk Jain grabbed $100,000 (over Rs 75.5 lakh) from Apple for discovering a now-patched Zero Day vulnerability in the Sign in with Apple account authentication.
The Zero Day vulnerability could have allowed a hacker to break into an Apple user’s account who log into third-party apps like Dropbox, Spotify, Airbnb and Giphy (now acquired by Facebook) and more.