# CVE-1999-1162: SCO UNIX passwd denial of service

Source: https://junglewise.ai/threats/cve-1999-1162-sco-unix-passwd-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 1993-05-24. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-1999-1162 · Severity: medium · CVSS 6.4 · Published 1993-05-24

A vulnerability in the password management utility of SCO UNIX 4.0 and earlier allows attackers to disrupt system access. By exploiting this flaw, an attacker can prevent legitimate users from logging into the system, effectively causing a denial of service. This could lead to significant operational downtime and prevent administrators from performing essential maintenance or security tasks.

Technologies: [Sco Unix](https://junglewise.ai/threats/technologies/unix). Vendors: [Sco](https://junglewise.ai/threats/vendors/sco).

## Quick answers

**Is CVE-1999-1162 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-1999-1162 being exploited in the wild.

**How severe is CVE-1999-1162?** Medium severity, with a CVSS score of 6.4, published 24 May 1993.

**Which products and versions are affected?** Sco Unix 4.0 and earlier.

**Is there a fix for CVE-1999-1162?** 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-1999-1162 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-1999-1162?** Check whether you run Sco Unix 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

The vulnerability exists within the 'passwd' command of SCO UNIX versions 4.0 and earlier. While specific technical root causes like buffer overflows were not explicitly detailed in the legacy advisory, the flaw allows an attacker to manipulate the password system in a way that locks out users. The attack vector is listed as network-reachable with low complexity and no authentication required. Successful exploitation results in a denial of service (DoS) affecting system availability and integrity. Patches were historically addressed in CERT advisory CA-1993-08.

## Affected products

- SCO UNIX 4.0 and earlier

## Timeline

- 1993-05-24: advisory: NVD published date
- 1993-12-31: advisory: CERT advisory CA-1993-08 published

## References

- [http://www.cert.org/advisories/CA-1993-08.html](http://www.cert.org/advisories/CA-1993-08.html)
- [http://www.iss.net/security_center/static/542.php](http://www.iss.net/security_center/static/542.php)

## Related threats

- [SCO UNIX privilege escalation in login](https://junglewise.ai/threats/cve-1999-1304-sco-unix-privilege-escalation-in-login)
- [SCO UNIX privilege escalation in at program](https://junglewise.ai/threats/cve-1999-1305-sco-unix-privilege-escalation-in-at-program)
- [SCO UNIX privilege escalation in prwarn](https://junglewise.ai/threats/cve-1999-1303-sco-unix-privilege-escalation-in-prwarn)
- [SCO UNIX privilege escalation in pt_chmod](https://junglewise.ai/threats/cve-1999-1302-sco-unix-privilege-escalation-in-pt-chmod)