Track vulnerabilities like this one. Sign up free to get alerted when software you use is affected.

CVE-2017-5567: Avast antivirus can be hijacked by local code injection

CVE-2017-5567 · published 9 years ago

Summary

A flaw in Avast Premier, Internet Security, Pro Antivirus and Free Antivirus versions 12.3 and earlier lets someone with local access bypass the program's self‑defense and insert their own code. This can give the attacker full control over the antivirus process. Install the latest Avast updates or patches that fix this weakness as soon as possible.

What to do

The CVE record does not list a fixed version. Check the vendor's site or the advisory links below - a fix may already be released.

Affected software

Vendor	Product	Affected versions
avast	free_antivirus	<= 12.3 `cpe:2.3:a:avast:free_antivirus::::::::`
avast	internet_security	<= 12.3 `cpe:2.3:a:avast:internet_security::::::::`
avast	premier	<= 12.3 `cpe:2.3:a:avast:premier::::::::`
avast	pro_antivirus	<= 12.3 `cpe:2.3:a:avast:pro_antivirus::::::::`

Original advisory text

Code injection vulnerability in Avast Premier 12.3 (and earlier), Internet Security 12.3 (and earlier), Pro Antivirus 12.3 (and earlier), and Free Antivirus 12.3 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and take full control of any Avast process via a "DoubleAgent" attack. One perspective on this issue is that (1) these products do not use the Protected Processes feature, and therefore an attacker can enter an arbitrary Application Verifier Provider DLL under Image File Execution Options in the registry; (2) the self-protection mechanism is intended to block all local processes (regardless of privileges) from modifying Image File Execution Options for these products; and (3) this mechanism can be bypassed by an attacker who temporarily renames Image File Execution Options during the attack.

References

http://cybellum.com/doubleagent-taking-full-control-antivirus/ Third Party Advisory
http://cybellum.com/doubleagentzero-day-code-injection-and-persistence-technique... Technical Description Third Party Advisory
http://www.securityfocus.com/bid/97017 Third Party Advisory VDB Entry

Fix within

Internet-facing 14 days

Internal At next upgrade

Not known to be exploited
Needs hands-on effort to exploit (estimated)
Gives an attacker full control (estimated)

Severity

6.7 Medium

Exploitation

<1% chance of attack within 30 days

Type

CWE-427Uncontrolled Search Path Element

Timeline

Published21 Mar 2017

Updated4 Nov 2026

First seen29 Sep 2026

Sources

CVE-2017-5567 · NVD

Track software like this

Free during beta