CVE-2019-17190

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2020-01-27 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:23 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2020-01-27 16:15 UTC

Last modified

2026-06-17 02:23 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-863 · Incorrect authorization

Record status

Modified

Affected

• Avast Secure Browser 76.0.1659.101

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2019-17190.md and follow it. Check whether this project is affected by CVE-2019-17190. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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