Antivirus Server
CVE-2020-9320
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V5 - File Handling File type validation, storage isolation
MITRE ATT&CK
2 techniques across 2 tactics: Command and Control, Persistence The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 5.5 (MEDIUM). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A local attacker with access to the system could upload malicious files that can be executed on the server. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Avira AV Engine before 8.3.54.138 allows virus-detection bypass via a crafted ISO archive. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate file types server-side, store uploads outside webroot, use random filenames, scan for malware.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Unrestricted File Upload (CWE-434), which allows attackers to upload malicious files that can be executed on the server. Avira AV Engine before 8.3.54.138 allows virus-detection bypass via a crafted ISO archive. This affects versions before 8.3.54.138 of Antivirus for Endpoint, Antivirus for Small Business, Exchange Security (Gateway), Internet Security Suite for Windows, Prime, Free Security Suite for Windows, and Cross Platform Anti-malware SDK. NOTE: Vendor asserts that vulnerability does not exist in product Affected products include: Avira Anti-Malware Sdk, Avira Antivirus Server, Avira Avira Antivirus For Endpoint, Avira Avira Antivirus For Small Business, Avira Avira Exchange Security. Version information: before 8.3.54.138.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Avira AV Engine before 8.3.54.138 allows virus-detection bypass via a crafted ISO archive. This affects versions before 8.3.54.138 of Antivirus for Endpoint, Antivirus for Small Business, Exchange Security (Gateway), Internet Security Suite for Windows, Prime, Free Security Suite for Windows, and Cross Platform Anti-malware SDK. NOTE: Vendor asserts that vulnerability does not exist in product
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Malicious file upload attacks exploit insufficient validation when web applications accept user-provided files.
GitHub PoC
Exploit-DB