MEDIUM
CVE-2020-13657
NVD-CWE-noinfoPublished: June 29, 2020· Updated: Jun 17, 2026
5.5
CVSS v3.1
Official Description
An elevation of privilege vulnerability exists in Avast Free Antivirus and AVG AntiVirus Free before 20.4 due to improperly handling hard links. The vulnerability allows local users to take control of arbitrary files.
Technical Analysis
CVE-2020-13657 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
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.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Affected Vendors & Products
avast2 product(s)
avg antivirusfree antivirus
Source: NVD CPE · 2 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://forum.avast.com/index.php?topic=232423.0Release Notes · Vendor Advisory
→
https://forum.avast.com/index.php?topic=234638.0Vendor Advisory
→
https://forum.avast.com/index.php?topic=232423.0Release Notes · Vendor Advisory
→
https://forum.avast.com/index.php?topic=234638.0Vendor Advisory
Quick Facts
CVE IDCVE-2020-13657
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessNVD-CWE-noinfo
CISA KEVNo
Affected1 vendor(s)
PublishedJun 29, 2020
Related CVEs (NVD-CWE-noinfo)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-13657 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.