An out-of-bounds write in the engine module in AVG/Avast Antivirus signature <24092400 released on 24/Sep/2024 on MacOS allows a malformed eml file to crash the application during file processing.

The AVGUI.exe of AVG/Avast Antivirus before versions before 24.1 can allow a local attacker to escalate privileges via an COM hijack in a time-of-check to time-of-use (TOCTOU) when self protection is disabled.

A sym-linked file accessed via the repair function in Avast Antivirus <24.2 on Windows may allow user to elevate privilege to delete arbitrary files or run processes as NT AUTHORITY\SYSTEM. The vulnerability exists within the "Repair" (settings -> troubleshooting -> repair) feature, which attempts to delete a file in the current user's AppData directory as NT AUTHORITY\SYSTEM. A low-privileged user can make a pseudo-symlink and a junction folder and point to a file on the system. This can provide a low-privileged user an Elevation of Privilege to win a race-condition which will re-create the system files and make Windows callback to a specially-crafted file which could be used to launch a privileged shell instance. This issue affects Avast Antivirus prior to 24.2.

Avast Premium Security Sandbox Protection Link Following Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Premium Security. 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 implementation of the sandbox feature. By creating a symbolic link, an attacker can abuse the service to create arbitrary namespace objects. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. . Was ZDI-CAN-20383.

Avast Premium Security Sandbox Protection Incorrect Authorization Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Premium Security. 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 implementation of the sandbox feature. The issue results from incorrect authorization. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code outside the sandbox at medium integrity. . Was ZDI-CAN-20178.

A time-of-check to time-of-use (TOCTOU) bug in handling of IOCTL (input/output control) requests. This TOCTOU bug leads to an out-of-bounds write vulnerability which can be further exploited, allowing an attacker to gain full local privilege escalation on the system.This issue affects Avast/Avg Antivirus: 23.8.

Buffer Overflow vulnerability in Avast AntiVirus before v.19.7 allows a local attacker to cause a denial of service via a crafted request to the aswSnx.sys driver.

Avast and AVG Antivirus for Windows were susceptible to a NULL pointer dereference issue via RPC-interface. The issue was fixed with Avast and AVG Antivirus version 22.11

Avast and AVG Antivirus for Windows were susceptible to a Time-of-check/Time-of-use (TOCTOU) vulnerability in the restore process leading to arbitrary file creation. The issue was fixed with Avast and AVG Antivirus version 22.11

Avast and AVG Antivirus for Windows were susceptible to a Time-of-check/Time-of-use (TOCTOU) vulnerability in the Quarantine process, leading to arbitrary file/directory deletion. The issue was fixed with Avast and AVG Antivirus version 22.11 and virus definitions from 14 February 2023 or later.