---
id: CVE-1999-1099
title: >-
  Kerberos 4 allows remote attackers to obtain sensitive information via a
  malformed UDP packet that generates an error string that inadvertently
  includes the realm name and the last user.
summary: >-
  Kerberos 4 allows remote attackers to obtain sensitive information via a
  malformed UDP packet that generates an error string that inadvertently
  includes the realm name and the last user.
severity: medium
cvss: 5
cvssVector: 'AV:N/AC:L/Au:N/C:P/I:N/A:N'
published: '1996-11-22'
updated: '2026-06-16'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-1999-1099'
references:
  - url: 'http://marc.info/?l=bugtraq&m=87602167420184&w=2'
    label: cve@mitre.org
  - url: 'https://exchange.xforce.ibmcloud.com/vulnerabilities/65'
    label: cve@mitre.org
  - url: 'http://marc.info/?l=bugtraq&m=87602167420184&w=2'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://exchange.xforce.ibmcloud.com/vulnerabilities/65'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01309
epssPercentile: 0.69366
ingestedAt: '2026-06-22T15:59:08.127Z'
---

## Overview

Kerberos 4 allows remote attackers to obtain sensitive information via a malformed UDP packet that generates an error string that inadvertently includes the realm name and the last user.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.