Avast Free Antivirus AvastSvc Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Free Antivirus. 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 Avast Service. By creating a symbolic link, an attacker can abuse the service to delete a folder. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-23731.

Avast Free Antivirus AvastSvc Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Free Antivirus. 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 Avast Service. By creating a symbolic link, an attacker can abuse the service to delete a folder. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-22963.

Avast Free Antivirus Link Following Denial-of-Service Vulnerability. This vulnerability allows local attackers to create a denial-of-service condition on affected installations of Avast Free Antivirus. 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 Avast Service. By creating a symbolic link, an attacker can abuse the service to create a folder. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-22806.

Avast Free Antivirus AvastSvc Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Free Antivirus. 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 Avast Service. By creating a symbolic link, an attacker can abuse the service to delete a file. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-22272.

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.

Avira Free Antivirus through 15.0.2005.1866 allows local users to discover user credentials. The functions of the executable file Avira.PWM.NativeMessaging.exe are aimed at collecting credentials stored in Chrome, Firefox, Opera, and Edge. The executable does not verify the calling program and thus a request such as fetchChromePasswords or fetchCredentials will succeed. NOTE: some third parties have stated that this is "not a vulnerability.

An issue was discovered in Avira Free-Antivirus before 15.0.2004.1825. The Self-Protection feature does not prohibit a write operation from an external process. Thus, code injection can be used to turn off this feature. After that, one can construct an event that will modify a file at a specific location, and pass this event to the driver, thereby defeating the anti-virus functionality.

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

Avira Free Antivirus 15.0.1907.1514 is prone to a local privilege escalation through the execution of kernel code from a restricted user.

Avast Free Antivirus prior to 19.1.2360 stores user credentials in memory upon login, which allows local users to obtain sensitive information by dumping AvastUI.exe application memory and parsing the data.