Apache HTTP Server 1.3.1 MIME Header Sioux denial of service

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.

A vulnerability, which was classified as critical, has been found in Apache HTTP Server 1.3.1 (Web Server). Affected by this issue is an unknown functionality of the component MIME Header Handler. The manipulation with an unknown input leads to a denial of service vulnerability (Sioux). Using CWE to declare the problem leads to CWE-404. The program does not release or incorrectly releases a resource before it is made available for re-use. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Apache WWW server 1.3.1 and earlier allows remote attackers to cause a denial of service (resource exhaustion) via a large number of MIME headers with the same name, aka the "sioux" vulnerability.

The weakness was shared 08/07/1998 as confirmed posting (Bugtraq). The advisory is shared for download at marc.theaimsgroup.com. This vulnerability is handled as CVE-1999-1199. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are unknown but a public exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 04/16/2019). The MITRE ATT&CK project declares the attack technique as T1499. This vulnerability has a historic impact due to its background and reception.

It is declared as highly functional. As 0-day the estimated underground price was around $5k-$25k.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at X-Force (8326) and Vulnerability Center (SBV-3292).






  • open-source

CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.4

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔍
VulDB Reliability: 🔍



VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍


Name: Sioux
Class: Denial of service / Sioux
CWE: CWE-404
ATT&CK: T1499

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍


08/07/1998 🔍
08/07/1998 +0 days 🔍
08/07/1998 +0 days 🔍
12/28/2003 +1969 days 🔍
06/19/2014 +3826 days 🔍
04/16/2019 +1762 days 🔍


Vendor: apache.org

Advisory: marc.theaimsgroup.com
Status: Confirmed
Confirmation: 🔍

CVE: CVE-1999-1199 (🔍)
X-Force: 8326
Vulnerability Center: 3292 - Apache WWW server <= 1.3.1 DoS, High

scip Labs: https://www.scip.ch/en/?labs.20161013


Created: 06/19/2014 05:11 PM
Updated: 04/16/2019 03:11 PM
Changes: 06/19/2014 05:11 PM (45), 04/16/2019 03:11 PM (16)
Complete: 🔍


No comments yet. Languages: en.

Please log in to comment.

Do you need the next level of professionalism?

Upgrade your account now!