PT-2021-17347 · Avast · Avast Premium Security

Abdelhamid Naceri · Published 2021-02-24 · Updated 2021-04-01 · CVE-2021-27241

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Name of the Vulnerable Software and Affected Versions: Avast Premium Security version 20.8.2429 (Build 20.8.5653.561)

Description: This issue allows local attackers to delete arbitrary directories on affected installations. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this issue. 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 issue to create a denial-of-service condition on the system.

Recommendations: For Avast Premium Security version 20.8.2429 (Build 20.8.5653.561), consider disabling the AvastSvc.exe module as a temporary workaround until a patch is available. Restrict access to the AvastSvc.exe module to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this issue.

Fix

Link Following

Weakness Enumeration

CWE-59

Related Identifiers

CVE-2021-27241

ZDI-21-208

Affected Products

Avast Premium Security

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2021-27241 · Security Note
• https://osv.dev/vulnerability/CVE-2021-27241 · Vendor Advisory
• https://zerodayinitiative.com/advisories/ZDI-21-208 · Security Note
• https://t.me/cvenotify/12267 · Telegram Post