Actively exploited vulnerability
Android OS: privilege escalation flaw under attack
CVE-2011-1823 · Android OS Privilege Escalation Vulnerability
What is affected
Android OS is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
The vold volume manager daemon in Android kernel trusts messages from a PF_NETLINK socket, which allows an attacker to execute code and gain root privileges. This vulnerability is associated with GingerBreak and Exploit.AndroidOS.Lotoor.
What an attacker can do
This is a privilege escalation flaw. It lets an attacker turn limited access into full administrator control. Attackers pair it with another flaw or a malicious file: once anything of theirs runs on the device, this bug lets it take over completely.
- How it is reached
- Needs access to the device or a file opened on it
- Access the attacker needs
- A basic user account
- Does the victim have to do something?
- No, works without the victim doing anything
What to do
- Update Android OS now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
Apply updates per vendor instructions.
Vendor advisories and fixes
- android.googlesource.comandroid.googlesource.com/platform/system/vold/+/c51920c82463b240e2be0430849837d6fdc5352e
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on September 8, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by September 29, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 41% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99% of all scored vulnerabilities.
Its CVSS severity score is 7.8 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
The vold volume manager daemon on Android 3.0 and 2.x before 2.3.4 trusts messages that are received from a PF_NETLINK socket, which allows local users to execute arbitrary code and gain root privileges via a negative index that bypasses a maximum-only signed integer check in the DirectVolume::handlePartitionAdded method, which triggers memory corruption, as demonstrated by Gingerbreak.