CVE-2021-27241

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.

• CVE ID
• CVE-2021-27241

• Assigner
• zdi-disclosures@trendmicro.com

• Vulnerability Status
• Analyzed

• Published Version
• 2021-03-29T21:15:12

• Last Modified Date
• 2021-04-01T16:04:36

• Version
• 2.0

• Vector String
• AV:L/AC:L/Au:N/C:N/I:P/A:P

• Access Vector
• LOCAL

• Access Compatibility
• LOW

• Authentication
• NONE

• Confidentiality Impact
• NONE

• Integrity Impact
• PARTIAL

• Availability Impact
• PARTIAL

• Base Score
• 3.6

• Severity
• LOW

• Exploitability Score
• 3.9

• Impact Score
• 4.9

• Version
• 3.1

• Vector String
• CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

• Attack Vector
• LOCAL

• Attack Compatibility
• LOW

• Privileges Required
• LOW

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• NONE

• Availability Impact
• HIGH

• Base Score
• 6.1

• Base Severity
• MEDIUM

• Exploitability Score
• 1.8

• Impact Score
• 4.2