# CVE-1999-1089: HP HP-UX buffer overflow in chfn command

Source: https://junglewise.ai/threats/cve-1999-1089-hp-hp-ux-buffer-overflow-in-chfn-command  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1996-12-13. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-1089 · Severity: high · CVSS 7.2 · Published 1996-12-13

A vulnerability in the 'chfn' command on older HP-UX operating systems allows a local user to gain full administrative (root) control of the system. The 'chfn' tool is used by users to change their finger information, such as their full name or office location. By providing an unexpectedly long input to this command, an attacker can crash the program and execute malicious code with elevated privileges, potentially leading to a complete system takeover.

Technologies: [Hp-Ux](https://junglewise.ai/threats/technologies/hp-ux). Vendors: [Hp](https://junglewise.ai/threats/vendors/hp).

## Quick answers

**Is CVE-1999-1089 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-1089 being exploited in the wild.

**How severe is CVE-1999-1089?** High severity, with a CVSS score of 7.2, published 13 December 1996.

**Which products and versions are affected?** Hp-Ux 9.X through 10.20.

**Is there a fix for CVE-1999-1089?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-1999-1089 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-1999-1089?** Check whether you run Hp-Ux at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stack-based buffer overflow exists in the 'chfn' utility, a setuid root program used to change user information. The vulnerability is triggered when the application fails to perform adequate bounds checking on command-line arguments. A local attacker can exploit this by passing a specially crafted, overly long string as an argument, allowing them to overwrite the return address on the stack and redirect execution flow. Because the binary is setuid root, successful exploitation results in arbitrary code execution with root privileges. This affects HP-UX versions 9.X through 10.20.

## Affected products

- HP HP-UX 9.X through 10.20

## Timeline

- 1996-12-09: disclosed: Exploit posted to Bugtraq mailing list by Aleph One
- 1996-12-13: advisory: NVD published date

## References

- [http://ciac.llnl.gov/ciac/bulletins/h-16.shtml](http://ciac.llnl.gov/ciac/bulletins/h-16.shtml)
- [http://ciac.llnl.gov/ciac/bulletins/h-21.shtml](http://ciac.llnl.gov/ciac/bulletins/h-21.shtml)
- [http://marc.info/?l=bugtraq&m=87602167420285&w=2](http://marc.info/?l=bugtraq&m=87602167420285&w=2)
- [https://exchange.xforce.ibmcloud.com/vulnerabilities/2008](https://exchange.xforce.ibmcloud.com/vulnerabilities/2008)

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