Squid Proxy 2.5 Stable/3 Pre NTLM Authentication ntlm_fetch_string denial of service

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Squid Proxy 2.5 Stable/3 Pre. This impacts the function ntlm_fetch_string of the component NTLM Authentication. This manipulation causes denial of service. This vulnerability appears as CVE-2004-0541. The attack may be initiated remotely. In addition, an exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Squid Proxy 2.5 Stable/3 Pre (Firewall Software) and classified as critical. Affected by this vulnerability is the function ntlm_fetch_string of the component NTLM Authentication. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

Buffer overflow in the ntlm_check_auth (NTLM authentication) function for Squid Web Proxy Cache 2.5.x and 3.x, when compiled with NTLM handlers enabled, allows remote attackers to execute arbitrary code via a long password ("pass" variable).

The bug was discovered 06/08/2004. The weakness was presented 09/03/2004 by Marco Ortisi with Squid Team (Website). It is possible to read the advisory at squid-cache.org. This vulnerability is known as CVE-2004-0541 since 06/04/2004. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

A public exploit has been developed in Perl Module. It is possible to download the exploit at securityfocus.com. It is declared as highly functional. The vulnerability was handled as a non-public zero-day exploit for at least 631 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 14524 (GLSA-200406-13 : Squid: NTLM authentication helper buffer overflow), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Gentoo Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 86485 (Squid Proxy NTLM Authentication Buffer Overflow Vulnerability).

Upgrading eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at www1.uk.squid-cache.org. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published even before and not after the disclosure of the vulnerability. Attack attempts may be identified with Snort ID 12362. In this case the pattern Proxy-Authorization|3A| NTLM TlRMTVNTUAADA is used for detection. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 2903.

The vulnerability is also documented in the databases at X-Force (16360), Exploit-DB (16847), Tenable (14524), SecurityFocus (BID 10500†) and OSVDB (9551†). Additional details are provided at www1.uk.squid-cache.org. See VDB-698 and VDB-22366 for similar entries. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
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Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 14524
Nessus Name: GLSA-200406-13 : Squid: NTLM authentication helper buffer overflow
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
Nessus Port: 🔍

OpenVAS ID: 52454
OpenVAS Name: FreeBSD Ports: squid
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: squid_ntlm_authenticate.rb
MetaSploit Name: Squid NTLM Authenticate Overflow
MetaSploit File: 🔍

ATK: 203
Exploit-DB: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Patch: www1.uk.squid-cache.org

Snort ID: 12362
Snort Message: EXPLOIT Squid HTTP Proxy-Authorization overflow
Snort Pattern: 🔍
TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

ISS Proventia IPS: 🔍
PaloAlto IPS: 🔍
Fortigate IPS: 🔍

Timelineinfo

09/25/2002 🔍
06/04/2004 +618 days 🔍
06/08/2004 +4 days 🔍
06/09/2004 +1 days 🔍
06/17/2004 +8 days 🔍
06/29/2004 +12 days 🔍
07/26/2004 +27 days 🔍
08/06/2004 +11 days 🔍
08/30/2004 +24 days 🔍
09/03/2004 +4 days 🔍
09/03/2004 +0 days 🔍
09/03/2004 +0 days 🔍
09/03/2004 +0 days 🔍
09/06/2004 +2 days 🔍
07/12/2025 +7614 days 🔍

Sourcesinfo

Vendor: squid-cache.org

Advisory: squid-cache.org
Researcher: Marco Ortisi
Organization: Squid Team
Status: Confirmed

CVE: CVE-2004-0541 (🔍)
GCVE (CVE): GCVE-0-2004-0541
GCVE (VulDB): GCVE-100-823

OVAL: 🔍

X-Force: 16360 - Squid Web Proxy Cache NTLM buffer overflow, High Risk
SecurityFocus: 10500 - Squid Proxy NTLM Authentication Buffer Overflow Vulnerability
Secunia: 12444 - Squid NTLM Authentication Denial of Service Vulnerability, Moderately Critical
OSVDB: 9551 - Squid NTLM Authentication Malformed NTLMSSP Packet DoS
SecurityTracker: 1011148
Vulnerability Center: 4853 - Buffer overflow in Ntlm_check_auth Function for Squid Web Proxy Cache 2.5.x and 3.x, Medium

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

Entryinfo

Created: 09/06/2004 11:32
Updated: 07/12/2025 20:25
Changes: 09/06/2004 11:32 (101), 06/29/2019 10:23 (20), 01/01/2025 02:37 (17), 07/12/2025 20:25 (2)
Complete: 🔍
Cache ID: 216:542:103

Be aware that VulDB is the high quality source for vulnerability data.

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