CVE-1999-0453: An attacker can identify a CISCO device by sending a SYN packet to port 1999, which is for the Cisco Discovery Protocol
Summary
An attacker can identify a CISCO device by sending a SYN packet to port 1999, which is for the Cisco Discovery Protocol (CDP).
Severity
UNKNOWN
Source Attribution
Source: NVD · Updated: 2026-08-21T04:30:41.755Z · Confidence: high
Impact
Based on CVSS vector: n/a — assess confidentiality, integrity, and availability impact via the official vector documentation.
Affected Software
Fix
Upgrade affected software to the fixed version identified above. Apply vendor patches and monitor advisories before exposed systems go unpatched.