CVE-2025-7003 Overview
CVE-2025-7003 is a heap buffer out-of-bounds read vulnerability in the Avira Antivirus engine. The flaw triggers when the engine scans a malformed PDF file, allowing 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 8.3.70.56. The vulnerability is tracked under CWE-125 (Out-of-bounds Read).
Critical Impact
A malformed PDF processed by the Avira scanning engine can crash the antivirus process or lead to local code execution, undermining the trust boundary of a security product running with elevated privileges.
Affected Products
- Avira Antivirus engine on Windows (builds before 8.3.70.56)
- Avira Antivirus engine on macOS (builds before 8.3.70.56)
- Avira Antivirus engine on Linux (builds before 8.3.70.56)
Discovery Timeline
- 2026-06-12 - CVE-2025-7003 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-7003
Vulnerability Analysis
The Avira Antivirus engine parses PDF files as part of its on-access and on-demand scanning workflows. A specially crafted PDF triggers a heap buffer out-of-bounds read inside the parser. The read accesses memory outside the bounds of an allocated heap buffer, returning data the parser does not own.
Depending on heap layout, the out-of-bounds read can leak adjacent memory or corrupt parser state. The advisory states the condition can result in local code execution or denial-of-service of the antivirus engine process. Crashes terminate scanning, leaving the host without active protection until the engine restarts.
Root Cause
The root cause is missing or incorrect bounds validation when the PDF parser reads structured data from an attacker-controlled file. Malformed length fields, object offsets, or stream descriptors drive the engine to read past the end of a heap allocation. This pattern aligns with CWE-125, where input-controlled indices are dereferenced without validating that the resulting address lies within the allocated buffer.
Attack Vector
The attack vector is local and requires user interaction. An attacker delivers a malformed PDF to the target system through email attachments, removable media, file shares, or web downloads. Once the file lands on disk, on-access scanning by the Avira engine parses it automatically, triggering the out-of-bounds read. No authentication is required because the antivirus engine processes files autonomously under its own service context.
No public exploit or proof-of-concept is currently available. See the GenDigital Security Advisory for vendor technical details.
Detection Methods for CVE-2025-7003
Indicators of Compromise
- Unexpected crashes or restarts of the Avira antivirus engine service or scanning process
- Presence of malformed or structurally invalid PDF files in user download, email attachment, or temporary directories
- Antivirus engine error logs referencing PDF parsing failures or access violations
Detection Strategies
- Monitor process exit codes and crash dumps for the Avira engine to flag repeated abnormal terminations
- Inspect PDF files at the email gateway or web proxy for structural anomalies before they reach endpoints
- Correlate antivirus service crashes with the arrival of new PDF files on the same host within a short time window
Monitoring Recommendations
- Enable verbose logging on the Avira engine and forward logs to a centralized SIEM for analysis
- Track the version string of the running Avira engine across the fleet to identify hosts still below build 8.3.70.56
- Alert on antivirus service stop events that are not initiated by an administrator or update process
How to Mitigate CVE-2025-7003
Immediate Actions Required
- Update the Avira Antivirus engine to build 8.3.70.56 or later on all Windows, macOS, and Linux endpoints
- Verify that automatic engine updates are enabled and reaching managed hosts
- Restrict delivery of untrusted PDF attachments at email and web gateways until patching is complete
Patch Information
Gen Digital has addressed the vulnerability in Avira Antivirus engine build 8.3.70.56. Administrators should confirm engine versions across their estate and force an update where the automatic mechanism has not applied the fix. Refer to the GenDigital Security Advisory for the authoritative patch notice.
Workarounds
- Where patching is delayed, block inbound PDF attachments at the mail transport layer for affected hosts
- Limit on-access scanning of files from untrusted origins until the engine is updated
- Isolate endpoints that repeatedly experience antivirus engine crashes pending investigation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
