CVE-1999-1090: High severity NCSA Telnet vulnerability

Published Sep 10, 1991
·
Updated

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.

Affected Software

2 affected componentsFixes available
NCSA Telnet
Microsoft cbl2 telnet 0.17-81

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Configuration

    Disable FTP in the NCSA Telnet configuration: remove any 'ftp=yes' line (or otherwise ensure FTP is not enabled) so the FTP service cannot be used to read or modify files.

    NCSA Telnet ftp = disabled
  2. Compensating control

    Until FTP is disabled in NCSA Telnet, restrict or block access to its FTP functionality from untrusted networks (for example via firewall rules or network ACLs limiting access to trusted hosts/networks).

Event History

Sep 10, 1991
CVE Published
04:00 AM
Data Sourced
via NVD·04:00 AM
RemedyDescriptionSeverityAffected Software
Mar 9, 2002
CVE Published
via MITRE·10:00 AM
Data Sourced
via MITRE·10:00 AM
Description
Oct 1, 2025
Data Sourced
via Microsoft·11:10 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·11:10 PM
Affected Software
Updated
via Microsoft·11:10 PM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-1999-1090?

CVE-1999-1090 is considered a high severity vulnerability due to the potential for remote file access by attackers.

2

How do I fix CVE-1999-1090?

To fix CVE-1999-1090, disable FTP support in the NCSA Telnet configuration or update to a patched version that addresses this issue.

3

What systems are affected by CVE-1999-1090?

CVE-1999-1090 affects versions of the NCSA Telnet package for Macintosh and PC.

4

What kind of attacks can occur due to CVE-1999-1090?

Attackers can exploit CVE-1999-1090 to read and modify arbitrary files on the affected systems.

5

Is there a workaround for CVE-1999-1090?

A temporary workaround for CVE-1999-1090 is to ensure that FTP is not enabled in any configuration used.

Contact

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