Product:
Snort 3 Detection Engine
Summary
Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly.
Details
| Severity | Base Score | CVE |
|---|---|---|
| MEDIUM | 5.8 | CVE-2026-20066 |
Exploitation
An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. By manipulating the HTTP packets, the attacker can trigger the error in the JSTokenizer normalization logic, leading to an unexpected restart of the Snort 3 Detection Engine and causing a denial of service.
Affected Products
- Snort 3 Detection Engine: Vulnerable to DoS attacks due to issues in HTTP packet parsing.
Mitigation
To mitigate this vulnerability, users should ensure that the JSTokenizer feature is disabled if it is not needed. Additionally, keeping the Snort 3 Detection Engine updated with the latest security patches from Cisco can help protect against this and other vulnerabilities.