MEDIUM
CVE-2020-9399
CWE-436Published: February 28, 2020· Updated: Jun 17, 2026
5.5
CVSS v3.1
Official Description
The Avast AV parsing engine allows virus-detection bypass via a crafted ZIP archive. This affects versions before 12 definitions 200114-0 of Antivirus Pro, Antivirus Pro Plus, and Antivirus for Linux.
Technical Analysis
CVE-2020-9399 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 5.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Affected Vendors & Products
avast3 product(s)
antivirus for linuxantivirus proantivirus pro plus
Source: NVD CPE · 3 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (4)
→
https://blog.zoller.lu/p/tzo-23-2020-avast-generic-archive.htmlThird Party Advisory
→
https://seclists.org/fulldisclosure/2020/Feb/35Mailing List · Third Party Advisory
→
https://blog.zoller.lu/p/tzo-23-2020-avast-generic-archive.htmlThird Party Advisory
→
https://seclists.org/fulldisclosure/2020/Feb/35Mailing List · Third Party Advisory
Quick Facts
CVE IDCVE-2020-9399
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessCWE-436
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 28, 2020
Related CVEs (CWE-436)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-9399 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.