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7.5High

Hilgraeve Hyperterminal

CVE-2000-0991

Buffer overflow in Hilgraeve, Inc. HyperTerminal client on Windows 98, ME, and 2000 allows remote attackers to execute arbitrary commands via a long telnet URL, aka the "HyperTerminal Buffer Overflow" vulnerability.

What this means for your business

  • It affects Hilgraeve Hyperterminal. It matters if your company, or a supplier that handles your data, runs it.
  • Code showing how to exploit it has been published, but real attacks have not been confirmed.
  • An attacker can use it remotely, over a network.

What to do

  1. 1Check whether your company or your suppliers run Hilgraeve Hyperterminal, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Check if you’re exposedBook a call

Scoring

CVSS
7.5 (v2.0)
Vector
AV:N/AC:L/Au:N/C:P/I:P/A:P
Assigned by
cve@mitre.org

Dates

Published
2000-12-19
Last modified
2026-09-23
Sources
NVD

Affected products

  • Hilgraeve Hyperterminal- 6.0

As listed in the NVD configuration data. Not a statement about your estate.

References