HOMEVULNERABILITIESCVE-2021-27241
MEDIUM

CVE-2021-27241

CWE-59Published: March 29, 2021· Updated: Jun 17, 2026

6.1
CVSS v3.1

Official Description

This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security 20.8.2429 (Build 20.8.5653.561). An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the AvastSvc.exe module. By creating a directory junction, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-12082.

NVD Source

Technical Analysis

CVE-2021-27241 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 availability disruption (denial of service), with a CVSS base score of 6.1.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityLow
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Affected Vendors & Products

avast1 product(s)
premium security
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
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Official Patches & Advisories

All References (2)

Quick Facts

CVE IDCVE-2021-27241
CVSS Score6.1 / 10
SeverityMEDIUM
WeaknessCWE-59
CISA KEVNo
Affected1 vendor(s)
PublishedMar 29, 2021

Related CVEs (CWE-59)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-27241 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.