AVAST Antivirus 25.11 contains an unquoted service path vulnerability in the SecureLine service that allows local non-privileged users to execute code with elevated SYSTEM privileges. Attackers can exploit the unquoted binary path in the service configuration to inject malicious executables that execute with high-level system permissions.

Integer Overflow or Wraparound vulnerability in Avast Antivirus (25.1.981.6) on Windows allows Privilege Escalation.This issue affects Antivirus: from 25.1.981.6 before 25.3.

NULL Pointer Dereference vulnerability in Avast Antivirus on MacOS, Avast Anitvirus on Linux when scanning a malformed Windows PE file causes the antivirus process to crash.This issue affects Antivirus: 16.0.0; Anitvirus: 3.0.3.

Improper preservation of permissions in the Avast sandbox minifilter driver (aswSnx.sys) on Windows allows a local, low-privileged attacker executing inside the sandbox to escape file isolation and escalate to SYSTEM.

When the sandbox virtualizes a file it copies the original security descriptor, but the driver opened the virtualization target object with GENERICWRITE and FILEWRITEATTRIBUTES only, omitting WRITEDAC. Every attempt to apply the original DACL therefore failed, and the failure was discarded silently, leaving virtualized copies of sensitive files with permissive permissions. Because the IRPMJCREATE callback additionally did not strip WRITEDAC for sensitive directories, a sandboxed process could rewrite the security descriptor of a virtualized object, read the virtualized copy of the SAM database, extract local NTLM password hashes and execute code as SYSTEM.

The absence of an IRPMJSETSECURITY callback in the driver's operation registration table is a related defense-in-depth gap, but it is not the control that prevents this attack.

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.

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.

The Avast AV parsing engine allows virus-detection bypass via a crafted ZIP archive. This affects versions before 12 definitions 200114-0 of Antivirus Pro, Antivirus Pro Plus, and Antivirus for Linux.

Avast AntiTrack before 1.5.1.172 and AVG Antitrack before 2.0.0.178 proxies traffic to HTTPS sites but does not validate certificates, and thus a man-in-the-middle can host a malicious website using a self-signed certificate. No special action necessary by the victim using AntiTrack with "Allow filtering of HTTPS traffic for tracking detection" enabled. (This is the default configuration.)

Code injection vulnerability in Avast Premier 12.3 (and earlier), Internet Security 12.3 (and earlier), Pro Antivirus 12.3 (and earlier), and Free Antivirus 12.3 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and take full control of any Avast process via a "DoubleAgent" attack. One perspective on this issue is that (1) these products do not use the Protected Processes feature, and therefore an attacker can enter an arbitrary Application Verifier Provider DLL under Image File Execution Options in the registry; (2) the self-protection mechanism is intended to block all local processes (regardless of privileges) from modifying Image File Execution Options for these products; and (3) this mechanism can be bypassed by an attacker who temporarily renames Image File Execution Options during the attack.

avast! antivirus 4.8.1281.0, when Internet Explorer 6 or 7 is used, allows remote attackers to bypass detection of malware in an HTML document by placing an MZ header (aka "EXE info") at the beginning, and modifying the filename to have (1) no extension, (2) a .txt extension, or (3) a .jpg extension, as demonstrated by a document containing a CVE-2006-5745 exploit.

The socket connection handler in aswArPot.sys in the Avast and AVG Windows Anti Rootkit driver before 22.1 allows local attackers to execute arbitrary code in kernel mode or cause a denial of service (memory corruption and OS crash) due to a double fetch vulnerability at aswArPot+0xc4a3.

The socket connection handler in aswArPot.sys in the Avast and AVG Windows Anti Rootkit driver before 22.1 allows local attackers to execute arbitrary code in kernel mode or cause a denial of service (memory corruption and OS crash) due to a double fetch vulnerability at aswArPot+0xbb94.

Aavmker4.sys in avast! 4.8 through 4.8.1368.0 and 5.0 before 5.0.418.0 running on Windows 2000 and XP does not properly validate input to IOCTL 0xb2d60030, which allows local users to cause a denial of service (system crash) or execute arbitrary code to gain privileges via IOCTL requests using crafted kernel addresses that trigger memory corruption.

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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-5424.

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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-5424.

Avast SecureLine 5.5.522.0 contains an unquoted service path vulnerability that allows local users to potentially execute code with elevated system privileges. Attackers can exploit the unquoted path in the service configuration to inject malicious code that would execute with LocalSystem account permissions during service startup.

Double fetch in sandbox kernel driver in Avast/AVG Antivirus <25.3  on windows allows local attacker to escalate privelages via pool overflow.

Link Following Local Privilege Escalation Vulnerability in NortonUtilitiesSvc in Norton Utilities Ultimate Version 24.2.16862.6344 on Windows 10 Pro x64 allows local attackers to escalate privileges and execute arbitrary code in the context of SYSTEM via the creation of a symbolic link and leveraging a TOCTTOU (time-of-check to time-of-use) attack.

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.

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.

This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2024-13961.

This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2024-13961.

This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2024-13962.

This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2024-13962.

Lack of file validation in doupdatevps in Avast Business Antivirus for Linux 4.5 on Linux allows local user to spoof or tamper with the update file via an unverified file write.

Link Following Local Privilege Escalation Vulnerability in TuneupSvc in Avast Cleanup Premium Version 24.2.16593.17810 on Windows 10 Pro x64 allows local attackers to escalate privileges and execute arbitrary code in the context of SYSTEM via creating a symbolic link and leveraging a TOCTTOU (time-of-check to time-of-use) attack.

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 ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2025-3500.

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 ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2025-3500.

The aswjsflt.dll library from Avast Antivirus windows contained a potentially exploitable heap corruption vulnerability that could enable an attacker to bypass the sandbox of the application it was loaded into, if applicable. This issue was fixed in version 18.0.1478 of the Script Shield Component.