CVE-2025-7007: 
Avast Antivirus vulnerability analysis and mitigation

CVE-2025-7007 is a NULL Pointer Dereference vulnerability in Avast Antivirus affecting macOS (version 16.0.0) and Linux (version 3.0.3) platforms. When the antivirus engine scans a specially crafted, malformed Windows PE file, it dereferences a null pointer, causing the antivirus process to crash. The vulnerability was published on December 1, 2025, and is assigned a CVSS v3.1 base score of 7.5 (High) (Red Hat CVE, EUVD).

The root cause is classified as CWE-476 (NULL Pointer Dereference), occurring in the PE file parsing logic of the Avast antivirus scanning engine on macOS and Linux. An attacker can craft a malformed Windows PE file that triggers the dereference when the scanner attempts to process invalid or missing data structures within the file. Exploitation requires local access, low privileges, user interaction (e.g., triggering a scan of the malicious file), and results in a changed scope — indicating the crash can affect components beyond the immediate scanning process (Red Hat CVE, EUVD). No public technical write-ups or PoC code have been identified at this time.

Successful exploitation causes the Avast antivirus process to crash, resulting in a denial of service for the security software itself. The CVSS scoring indicates high impacts across confidentiality, integrity, and availability with a changed scope, suggesting the crash could potentially affect dependent system components or leave the host temporarily unprotected. The primary risk is disruption of endpoint protection, which could be leveraged as a precursor to further attacks while the antivirus is non-functional (Red Hat CVE).

1. Craft malformed PE file: Create a Windows PE file with intentionally malformed or missing header structures (e.g., invalid section headers, null data directory entries) designed to trigger a null pointer dereference in Avast's parsing logic.
2. Deliver the file: Place the malformed PE file on the target macOS (Avast 16.0.0) or Linux (Avast 3.0.3) system via any accessible means — email attachment, shared drive, USB, or download — to a location accessible to the target user.
3. Trigger a scan: Induce the Avast antivirus engine to scan the malicious file, either by waiting for real-time protection to scan it automatically upon access, or by convincing the user to initiate a manual scan of the file or its containing directory.
4. Cause process crash: The antivirus engine dereferences a null pointer while parsing the malformed PE file, causing the antivirus process to crash and temporarily disabling endpoint protection on the host.

• File System: Presence of a malformed or anomalous Windows PE file (e.g., with invalid headers, zero-length sections, or corrupt data directories) on a macOS or Linux system running Avast Antivirus.
• Logs: Avast antivirus crash logs or core dump files generated around the time of scanning a suspicious PE file; system logs (e.g., /var/log/syslog, macOS Console) showing unexpected termination of the Avast process.
• Process: Unexpected termination or absence of the Avast antivirus daemon/process (avast, avastd, or equivalent) without a user-initiated stop.

Gen Digital (Avast's parent company) is the assigning authority (NLOK) for this CVE; users should consult the official Gen Digital security advisories page for patch availability and updated version information (Gen Digital Advisories). Until a patch is confirmed and applied, administrators should ensure Avast is kept up to date via automatic updates, restrict local user access to untrusted PE files, and monitor for unexpected antivirus process crashes. As a workaround, consider supplementing Avast with additional endpoint security controls to maintain protection if the antivirus process crashes.

The vulnerability received brief attention on social media shortly after disclosure, with a mention noted on Mastodon (infosec.exchange) on December 1, 2025. CISA included it in its weekly vulnerability summary bulletin for the week of December 1, 2025 (CISA Bulletin). No significant vendor statements beyond the CVE assignment or notable researcher commentary have been identified.