CVE-2019-17190 Privilege escalation in n/a
A local attacker can escalate privileges to SYSTEM by exploiting insecure ACLs on an update configuration file in Avast Secure Browser.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2019-17190?
CVE-2019-17190 is a high-severity vulnerability in n/a, published on 27 Jan 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A Local Privilege Escalation issue was discovered in Avast Secure Browser 76.0.1659.101. The vulnerability is due to an insecure ACL set by the AvastBrowserUpdate.exe (which is running as NT AUTHORITY\SYSTEM) when AvastSecureBrowser.exe checks for new updates. When the update check is triggered, the elevated process cleans the ACL of the Update.ini file in %PROGRAMDATA%\Avast Software\Browser\Update\ and sets all privileges to group Everyone. Because any low-privileged user can create, delete, or modify the Update.ini file stored in this location, an attacker with low privileges can create a hard link named Update.ini in this folder, and make it point to a file writable by NT AUTHORITY\SYSTEM. Once AvastBrowserUpdate.exe is triggered by the update check functionality, the DACL is set to a misconfigured value on the crafted Update.ini and, consequently, to the target file that was previously not writable by the low-privileged attacker.
Weakness: CWE-863
Which versions are affected by CVE-2019-17190?
It affects 1 product.
Products include Avast Secure Browser.
How do I fix CVE-2019-17190?
No fix has been published for CVE-2019-17190 yet. Limit exposure of the affected software until one is available.
Is CVE-2019-17190 being exploited?
There is no known exploitation of CVE-2019-17190 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-q9mx-5pvj-qh3x.