Squid Web Proxy up to 4.12/5.0.3 Cache HTTPS Traffic request smuggling

Summaryinfo

A vulnerability classified as critical has been found in Squid Web Proxy up to 4.12/5.0.3. Affected is an unknown function of the component Cache Handler. This manipulation as part of HTTPS Traffic causes request smuggling. This vulnerability is handled as CVE-2020-15811. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Squid Web Proxy up to 4.12/5.0.3 (Firewall Software). It has been declared as critical. Affected by this vulnerability is some unknown processing of the component Cache Handler. The manipulation as part of a HTTPS Traffic leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.

The weakness was released 09/02/2020 (Website). The advisory is shared at debian.org. This vulnerability is known as CVE-2020-15811 since 07/17/2020. The attack can be launched remotely. Required for exploitation is a single authentication. Neither technical details nor an exploit are publicly available.

Upgrading to version 4.13 or 5.0.4 eliminates this vulnerability.

Entry connected to this vulnerability is available at VDB-160620. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Firewall Software

Vendor

• Squid

Name

• Web Proxy

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3

License

• open-source

Website

• Vendor: http://www.squid-cache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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

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