CVE-1999-1228: Various modems that do not implement a guard time, or are configured with a guard time of 0, can allow remote attackers

Published n/a Updated 2026-08-21T04:30:41.069Z

Summary

Various modems that do not implement a guard time, or are configured with a guard time of 0, can allow remote attackers to execute arbitrary modem commands such as ATH, ATH0, etc., via a "+++" sequence that appears in ICMP packets, the subject of an e-mail message, IRC commands, and others.

Severity

UNKNOWN

Source Attribution

Source: NVD · Updated: 2026-08-21T04:30:41.069Z · 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.

References