Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target.
References
| Link | Resource |
|---|---|
| https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html | Third Party Advisory |
| https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions | Release Notes |
| https://www.avira.com/en/internet-security | Product |
| https://www.vulncheck.com/advisories/avira-internet-security-optimizer-toctou | Third Party Advisory |
Configurations
History
No history.
Information
Published : 2026-03-05 15:16
Updated : 2026-03-13 01:19
NVD link : CVE-2026-27750
Mitre link : CVE-2026-27750
CVE.ORG link : CVE-2026-27750
JSON object : View
Products Affected
avira
- internet_security
CWE
CWE-367
Time-of-check Time-of-use (TOCTOU) Race Condition