CVE-2025-9032: Avira Antivirus Engine RCE Vulnerability

CVE-2025-9032 Overview

CVE-2025-9032 is a heap buffer out-of-bounds read vulnerability in the Avira Antivirus engine. The flaw is triggered when the engine scans a malformed Windows Portable Executable (PE) file. Successful exploitation can lead to local code execution or denial-of-service of the antivirus engine process.

The issue affects Avira Antivirus on Windows, macOS, and Linux for engine builds before 8.3.70.98. The vulnerability is classified as an out-of-bounds read [CWE-125]. Because antivirus engines automatically scan files placed on disk, an attacker who can drop a crafted PE file may trigger the condition without user interaction beyond standard file activity.

Critical Impact
A malformed PE file scanned by the Avira engine can cause heap memory disclosure, antivirus process termination, or local code execution within the antivirus engine context.

Affected Products

Avira Antivirus engine on Windows (builds before 8.3.70.98)
Avira Antivirus engine on macOS (builds before 8.3.70.98)
Avira Antivirus engine on Linux (builds before 8.3.70.98)

Discovery Timeline

2026-06-12 - CVE-2025-9032 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-9032

Vulnerability Analysis

The Avira Antivirus engine parses Windows PE files during on-access and on-demand scans. The vulnerability arises when the engine processes a malformed PE structure and reads beyond the bounds of an allocated heap buffer. This out-of-bounds read [CWE-125] can leak adjacent heap memory, destabilize the scanner process, or be combined with additional primitives to influence control flow.

Because antivirus engines run with elevated privileges to inspect arbitrary files, a successful local code execution outcome inherits those privileges. The denial-of-service outcome disables real-time protection on the affected host, which leaves the system exposed to subsequent malware that the engine would normally block.

Root Cause

The root cause is missing or insufficient bounds checking while parsing fields within a malformed PE file. Attacker-controlled size or offset values in the PE headers, section tables, or directory entries cause the parser to dereference memory outside the allocated buffer. Refer to the Gen Digital Security Advisory for vendor-supplied technical context.

Attack Vector

The attack vector is local. An attacker places a crafted PE file on the target system through any delivery method the engine subsequently scans, including downloads, email attachments saved to disk, USB media, or shared folders. User interaction is required to introduce the file into a scanned location, after which the engine processes the file automatically.

No verified public proof-of-concept code is available for this issue. See the vendor advisory referenced above for additional technical detail.

Detection Methods for CVE-2025-9032

Indicators of Compromise

Unexpected crashes or restarts of the Avira engine process on Windows, macOS, or Linux endpoints.
Antivirus scan logs showing repeated failures or terminations when processing specific files.
Presence of malformed PE files in user-writable directories, temp folders, or download paths immediately before scanner instability.

Detection Strategies

Inventory installed Avira engine versions across endpoints and flag any host running an engine build older than 8.3.70.98.
Correlate antivirus process crash events with file-write events for .exe, .dll, and other PE file types to identify potential trigger files.
Hunt for processes spawning from or interacting with the antivirus engine in anomalous ways, which may indicate post-exploitation activity following local code execution.

Monitoring Recommendations

Forward antivirus engine logs and Windows Application/Event logs to a centralized SIEM and alert on engine termination events.
Monitor endpoint telemetry for files written immediately before antivirus engine faults and quarantine those artifacts for analysis.
Track patch deployment status of Avira engine builds as a compliance metric until all hosts reach 8.3.70.98 or later.

How to Mitigate CVE-2025-9032

Immediate Actions Required

Update the Avira Antivirus engine on all Windows, macOS, and Linux endpoints to build 8.3.70.98 or later.
Verify that automatic engine updates are enabled and successfully completing on every managed host.
Audit endpoints for the presence of the vulnerable engine build and prioritize remediation on systems that handle untrusted files.

Patch Information

Gen Digital has released a fixed engine build numbered 8.3.70.98. Engine updates are distributed through standard Avira update channels. Confirmation of the deployed engine version should be performed after the update completes. Consult the Gen Digital Security Advisory for the authoritative patch notice.

Workarounds

Restrict the introduction of untrusted PE files to endpoints by enforcing application allowlisting and controlling removable media.
Limit user permissions so that arbitrary executables cannot be written to scanned directories on shared systems.
Temporarily exclude high-risk untrusted file repositories from on-access scanning only as a short-term measure, and revert the exclusion immediately after patching.

bash

# Verify the installed Avira engine build on Linux
avira-update --info | grep -i "engine"

# Trigger an engine update
sudo avira-update