CVE-1999-0661

CVE-1999-0661 is a critical-severity vulnerability with a CVSS 2.0 base score of 10.0. Its EPSS exploit-prediction score of 54% places it in the 99th percentile, indicating an elevated likelihood of exploitation.

Key facts

Description

A system is running a version of software that was replaced with a Trojan Horse at one of its distribution points, such as (1) TCP Wrappers 7.6, (2) util-linux 2.9g, (3) wuarchive ftpd (wuftpd) 2.2 and 2.1f, (4) IRC client (ircII) ircII 2.2.9, (5) OpenSSH 3.4p1, or (6) Sendmail 8.12.6.

Frequently asked questions

What is CVE-1999-0661?
A system is running a version of software that was replaced with a Trojan Horse at one of its distribution points, such as (1) TCP Wrappers 7.6, (2) util-linux 2.9g, (3) wuarchive ftpd (wuftpd) 2.2 and 2.1f, (4) IRC client (ircII) ircII 2.2.9, (5) OpenSSH 3.4p1, or (6) Sendmail 8.12.6.
How severe is CVE-1999-0661?
CVE-1999-0661 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-1999-0661 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 54% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-1999-0661?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-1999-0661 published?
CVE-1999-0661 was published on 1999-01-01 and last updated on 2026-06-16.

References