CVE-1999-0063

NONECVSS 0.0Weaponized

0.0

Cisco IOS 12.0 and other versions can be crashed by malicious UDP packets to the syslog port.

CVSS v3: —
EG Score: —
EPSS: 93.9%
KEV: Not listed

Published

January 11, 1999

Last Modified

April 16, 2026

References (2)

cve@mitrehttps://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0063
af854a3a-2127-422b-91ae-364da2661108https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0063

Data Freshness Timeline

(refreshed 13× in last 7d / 19× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-29 13:40 UTCepss_batch
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Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

Exploit-DBEDB-19531✓ verified
First seen Jan 11, 1999
Cisco IOS 12.0.2 - Syslog Crash
Open source ↗

Frequently asked(4)

What is CVE-1999-0063?

CVE-1999-0063 is a none vulnerability published on January 11, 1999. Cisco IOS 12.0 and other versions can be crashed by malicious UDP packets to the syslog port.

When was CVE-1999-0063 disclosed?

CVE-1999-0063 was first published in the National Vulnerability Database on January 11, 1999, with the most recent update on April 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-1999-0063 actively exploited?

CVE-1999-0063 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

How do I remediate CVE-1999-0063?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-1999-0063, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-1999-0063

📅 Published

🔄 Last Modified

🔗 References (2)