Apache HTTP Server up to 1.3.20 mod_usertrack improper authentication

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.
3.8	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Apache HTTP Server up to 1.3.20 and classified as problematic. Affected by this vulnerability is an unknown functionality of the component mod_usertrack. Performing a manipulation results in improper authentication. This vulnerability was named CVE-2001-1534. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apache HTTP Server up to 1.3.20 (Web Server). It has been classified as problematic. This affects an unknown part of the component mod_usertrack. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality. The summary by CVE is:

mod_usertrack in Apache 1.3.11 through 1.3.20 generates session ID s using predictable information including host IP address, system time and server process ID, which allows local users to obtain session ID s and bypass authentication when these session ID s are used for authentication.

The weakness was presented 12/31/2001 by David Endler as not defined posting (Bugtraq). The advisory is shared at cert.uni-stuttgart.de. This vulnerability is uniquely identified as CVE-2001-1534 since 07/14/2005. The exploitability is told to be easy. An attack has to be approached locally. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 86274 (Apache mod_usertrack Predictable ID Generation Vulnerability).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at X-Force (7494), SecurityFocus (BID 3521†) and Vulnerability Center (SBV-3624†). See VDB-17854 for similar entry. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Web Server

Vendor

• Apache

Name

• HTTP Server

Version

• 1.3.0
• 1.3.1
• 1.3.2
• 1.3.3
• 1.3.4
• 1.3.5
• 1.3.6
• 1.3.7
• 1.3.8
• 1.3.9
• 1.3.10
• 1.3.11
• 1.3.12
• 1.3.13
• 1.3.14
• 1.3.15
• 1.3.16
• 1.3.17
• 1.3.18
• 1.3.19
• 1.3.20

License

• open-source

Support

• end of life (old version)

Website

• Vendor: https://www.apache.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 3.8

VulDB Base Score: 4.0
VulDB Temp Score: 3.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

11/08/2001 🔍
12/31/2001 +53 days 🔍
12/31/2001 +0 days 🔍
01/01/2003 +366 days 🔍
01/28/2004 +392 days 🔍
07/14/2005 +533 days 🔍
07/11/2014 +3284 days 🔍
09/24/2025 +4093 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: cert.uni-stuttgart.de
Researcher: David Endler
Status: Confirmed

CVE: CVE-2001-1534 (🔍)
GCVE (CVE): GCVE-0-2001-1534
GCVE (VulDB): GCVE-100-17853
X-Force: 7494
SecurityFocus: 3521 - Apache mod_usertrack Predictable ID Generation Vulnerability
Vulnerability Center: 3624 - Apache mod_usertrack Module Generates Predictable ID Numbers, Medium

See also: 🔍

Entryinfo

Created: 07/11/2014 13:29
Updated: 09/24/2025 12:41
Changes: 07/11/2014 13:29 (42), 05/19/2019 15:28 (21), 09/24/2025 12:41 (20)
Complete: 🔍
Cache ID: 216::103

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Discussion

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