How severe is CVE-1999-1090?

CVE-1999-1090 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-1090 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1090?

CVE-1999-1090 affects Ncsa Telnet. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-1090?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-1999-1090 published?

CVE-1999-1090 was published on 1991-09-10 and last updated on 2026-06-16.

CVE-1999-1090

CVE-1999-1090 is a high-severity vulnerability in Ncsa Telnet with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Ncsa Telnet
Published: 1991-09-10
Last modified: 2026-06-16

Description

The default configuration of NCSA Telnet package for Macintosh and PC enables FTP, even though it does not include an "ftp=yes" line, which allows remote attackers to read and modify arbitrary files.

Frequently asked questions

What is CVE-1999-1090?: The default configuration of NCSA Telnet package for Macintosh and PC enables FTP, even though it does not include an "ftp=yes" line, which allows remote attackers to read and modify arbitrary files.
How severe is CVE-1999-1090?: CVE-1999-1090 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-1090 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1090?: CVE-1999-1090 affects Ncsa Telnet. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-1090?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-1999-1090 published?: CVE-1999-1090 was published on 1991-09-10 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:ncsa:telnet:*:*:*:*:*:*:*:*

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