Squid Proxy up to 3.5.22/4.0.16 Header Comparison information disclosure

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.
6.3	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Squid Proxy up to 3.5.22/4.0.16. Affected by this issue is some unknown functionality of the component Header Comparison. This manipulation causes information disclosure. This vulnerability is handled as CVE-2016-10003. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Squid Proxy up to 3.5.22/4.0.16 (Firewall Software) and classified as problematic. Affected by this vulnerability is an unknown functionality of the component Header Comparison. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

Incorrect HTTP Request header comparison in Squid HTTP Proxy 3.5.0.1 through 3.5.22, and 4.0.1 through 4.0.16 results in Collapsed Forwarding feature mistakenly identifying some private responses as being suitable for delivery to multiple clients.

The bug was discovered 12/16/2016. The weakness was released 12/16/2016 by Felix Hassert as SQUID-2016:10 as confirmed advisory (Website). It is possible to read the advisory at squid-cache.org. This vulnerability is known as CVE-2016-10003 since 12/17/2016. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK. The advisory points out:

This problem allows a remote attacker to discover private and sensitive information about another clients browsing session. Potentially including credentials which allow access to further sensitive resources.

The vulnerability scanner Nessus provides a plugin with the ID 96622 (openSUSE Security Update : squid (openSUSE-2017-115)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169490 (SUSE Enterprise Linux Security Update for squid (SUSE-SU-2017:0128-1)). The advisory illustrates:

This problem only affects Squid configured to use the Collapsed Forwarding feature. (...) The following command can be used to determine if Squid-3 or later have collapsed_forwarding in squid.conf: (squid -k parse 2>&1) | grep collapsed_forwarding

Upgrading to version 3.5.23 or 4.0.17 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (96622), SecurityFocus (BID 94953†) and SecurityTracker (ID 1037512†). Entries connected to this vulnerability are available at VDB-92483 and VDB-94710. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Firewall Software

Vendor

• Squid

Name

• Proxy

Version

• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.5.5
• 3.5.6
• 3.5.7
• 3.5.8
• 3.5.9
• 3.5.10
• 3.5.11
• 3.5.12
• 3.5.13
• 3.5.14
• 3.5.15
• 3.5.16
• 3.5.17
• 3.5.18
• 3.5.19
• 3.5.20
• 3.5.21
• 3.5.22
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11
• 4.0.12
• 4.0.13
• 4.0.14
• 4.0.15
• 4.0.16

License

• open-source

Website

• Vendor: http://www.squid-cache.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

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: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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

Nessus ID: 96622
Nessus Name: openSUSE Security Update : squid (openSUSE-2017-115)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 65643
OpenVAS Name: Squid Information Disclosure Vulnerability (Linux)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: Proxy 3.5.23/4.0.17
Workaround: Remove all uses of 'collapsed_forwarding' from squid.conf and included sub-files.

Timelineinfo

12/16/2016 🔍
12/16/2016 +0 days 🔍
12/16/2016 +0 days 🔍
12/17/2016 +1 days 🔍
12/17/2016 +0 days 🔍
12/21/2016 +4 days 🔍
12/29/2016 +8 days 🔍
01/19/2017 +21 days 🔍
01/27/2017 +8 days 🔍
05/15/2026 +3394 days 🔍

Sourcesinfo

Vendor: squid-cache.org

Advisory: SQUID-2016:10
Researcher: Felix Hassert
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-10003 (🔍)
GCVE (CVE): GCVE-0-2016-10003
GCVE (VulDB): GCVE-100-94711
SecurityFocus: 94953 - Squid HTTP proxy Multiple Information Disclosure Vulnerabilities
SecurityTracker: 1037512

See also: 🔍

Entryinfo

Created: 12/29/2016 18:25
Updated: 05/15/2026 00:52
Changes: 12/29/2016 18:25 (81), 07/21/2019 17:40 (10), 05/15/2026 00:52 (17)
Complete: 🔍
Cache ID: 216::103

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

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