CVE-2019-18894: avast premium_security OS Command Injection

Vulnerability summary

CVE-2019-18894 is a high (CVSS 9.3) OS Command Injection vulnerability in avast premium_security. EPSS estimates a 1.78% chance of exploitation in the next 30 days, higher than 77.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 13-01-2020
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

Description

In Avast Premium Security 19.8.2393, attackers can send a specially crafted request to the local web server run by Avast Antivirus on port 27275 to support Bank Mode functionality. A flaw in the processing of a command allows execution of arbitrary OS commands with the privileges of the currently logged in user. This allows for example attackers who compromised a browser extension to escape from the browser sandbox.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.