Vulnerability in Avast Free Antivirus
CVE-2017-5567
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
Weakness classification (CWE)
References
- cybellum.com/doubleagent-taking-full-control-antivirus/ (Third Party Advisory)
- www.securityfocus.com/bid/97017 (VDB Entry, Third Party Advisory, vdb-entry)
- cybellum.com/doubleagentzero-day-code-injection-and-persistence-technique/ (Technical Description, Third Party Advisory)
Frequently asked questions
- What is CVE-2017-5567?
- CVE-2017-5567 is a medium-severity vulnerability in Avast Free Antivirus, classified under Uncontrolled Search Path Element. CVSS score: 6.7/10. Published 2017-03-21.
- How severe is CVE-2017-5567?
- Medium severity. CVSS v3 base score is 6.7 out of 10.