Apache HTTP Server up to 2.0.50 mod_ssl infinite loop

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.
6.7$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Apache HTTP Server up to 2.0.50. The impacted element is an unknown function of the component mod_ssl. The manipulation leads to infinite loop. This vulnerability is documented as CVE-2004-0748. The attack can be initiated remotely. Additionally, an exploit exists. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apache HTTP Server up to 2.0.50 (Web Server). This issue affects some unknown functionality of the component mod_ssl. The manipulation with an unknown input leads to a infinite loop vulnerability. Using CWE to declare the problem leads to CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. Impacted is availability. The summary by CVE is:

mod_ssl in Apache 2.0.50 and earlier allows remote attackers to cause a denial of service (CPU consumption) by aborting an SSL connection in a way that causes an Apache child process to enter an infinite loop.

The weakness was released 09/01/2004 by Francis Wai, Keil Hartmut and M. "Alex" Hankins with Red Hat (Website). The advisory is shared at rhn.redhat.com. The identification of this vulnerability is CVE-2004-0748 since 07/26/2004. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are unknown but a public exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

After 2 weeks, there has been an exploit disclosed. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 14624 (RHEL 3 : httpd (RHSA-2004:349)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Red Hat Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 86678 (Multiple Apache Web Server Vulnerabilities prior to version 2.0.51).

Upgrading to version 1 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at nagoya.apache.org. The best possible mitigation is suggested to be patching the affected component.

The vulnerability is also documented in the databases at X-Force (17200), Tenable (14624), SecurityFocus (BID 11094†), OSVDB (9742†) and Secunia (SA12434†). httpd.apache.org is providing further details. Entry connected to this vulnerability is available at VDB-22310. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Support

  • end of life (old version)

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 6.7

VulDB Base Score: 7.5
VulDB Temp Score: 6.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 14624
Nessus Name: RHEL 3 : httpd (RHSA-2004:349)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Port: 🔍

OpenVAS ID: 52331
OpenVAS Name: FreeBSD Ports: apache
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

ATK: 137

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍
Exploit Delay Time: 🔍

Upgrade: HTTP Server 1
Patch: nagoya.apache.org
PaloAlto IPS: 🔍

Timelineinfo

07/26/2004 🔍
09/01/2004 +37 days 🔍
09/01/2004 +0 days 🔍
09/01/2004 +0 days 🔍
09/02/2004 +1 days 🔍
09/02/2004 +0 days 🔍
09/02/2004 +0 days 🔍
09/07/2004 +5 days 🔍
09/10/2004 +2 days 🔍
09/11/2004 +1 days 🔍
09/21/2004 +10 days 🔍
10/20/2004 +29 days 🔍
07/11/2025 +7569 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: rhn.redhat.com
Researcher: Francis Wai, Keil Hartmut, M. "Alex" Hankins
Organization: Red Hat
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2004-0748 (🔍)
GCVE (CVE): GCVE-0-2004-0748
GCVE (VulDB): GCVE-100-821

OVAL: 🔍

X-Force: 17200 - Apache HTTP Server mod_ssl denial of service, Medium Risk
SecurityFocus: 11094 - Apache mod_ssl Denial Of Service Vulnerability
Secunia: 12434 - Apache 2 mod_ssl Denial of Service Vulnerabilities, Less Critical
OSVDB: 9742 - Apache HTTP Server mod_ssl char_buffer_read Function Reverse Proxy DoS
SecurityTracker: 1011213 - Apache mod_ssl Can Be Crashed By Remote Users When Reverse Proxying SSL Connections
Vulnerability Center: 5436 - DoS in Apache 2.0.50 mod_ssl via Aborted SSL Connections, High

scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔍
See also: 🔍

Entryinfo

Created: 09/02/2004 16:22
Updated: 07/11/2025 20:54
Changes: 09/02/2004 16:22 (96), 04/16/2019 15:10 (13), 03/09/2021 17:32 (3), 07/11/2025 20:54 (16)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Are you interested in using VulDB?

Download the whitepaper to learn more about our service!