Microsoft has recently addressed an important vulnerability, tracked as CVE-2019-1105, in Outlook for Android, that potentially affected over 100 million users.
The vulnerability is a stored cross-site scripting issue that is related to the way the app parses incoming email messages.
“A spoofing vulnerability exists in the way Microsoft Outlook for Android software parses specifically crafted email messages. An authenticated attacker could exploit the vulnerability by sending a specially crafted email message to a victim.” reads the security advisory published by Microsoft.
“The attacker who successfully exploited this vulnerability could then perform cross-site scripting attacks on the affected systems and run scripts in the security context of the current user.”
An attacker could exploit the vulnerability by sending a specially crafted message to the victim and run malicious code in the context of the current user. The vulnerability could potentially lead to spoofing attacks.
The spoofing issue in Outlook was separately reported by multiple security researchers, including the researcher Bryan Appleby from F5 Networks that now released more details and proof-of-concept for the flaw. Appleby reported the vulnerability to Microsoft six months ago and explained in a post how he discovered the issue.
The experts pointed out that the flaw affected the way email server parses HTML entities included in the email messages.
The bug allowed the expert to steal data from the app, he exploited it to read and extract the HTML.
“This code can do whatever the attacker desires, up to and including stealing information and/or sending data back out. An attacker can send you an email and just by you reading it, they could steal the contents of your inbox. Weaponized, this can turn into a very nasty piece of malware.”
Below the timeline of the flaw:
Appleby also shared a PoC with the tech giant.