What’s Vulnerable › Vulnerabilities

CVE-2017-5567

• Severity: medium (CVSS 6.7 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2017-03-21 · updated 2026-06-17
• Weakness: CWE-427

Description

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.

Affected products

• Avast Free Antivirus: through 12.3
• Avast Internet Security: through 12.3
• Avast Premier: through 12.3
• Avast Pro Antivirus: through 12.3

References

• http://cybellum.com/doubleagent-taking-full-control-antivirus/
• http://cybellum.com/doubleagentzero-day-code-injection-and-persistence-technique/
• http://www.securityfocus.com/bid/97017
• http://cybellum.com/doubleagent-taking-full-control-antivirus/
• http://cybellum.com/doubleagentzero-day-code-injection-and-persistence-technique/
• http://www.securityfocus.com/bid/97017

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