CVE-2019-12520

CVE Details

Release Date:

2020-04-15

Description

An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI.

See more information about CVE-2019-12520 from MITRE CVE dictionary and NIST NVD

CVSS v3.0 metrics

NOTE: The following CVSS v3.0 metrics and score provided are preliminary and subject to review.

Base Score:	7.5	Base Metrics:	AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Access Vector:	Network	Attack Complexity:	Low
Privileges Required:	None	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	High
Integrity Impact:	None	Availability Impact:	None

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (squid)	ELSA-2022-22254	2022-10-03
Oracle Linux version 8 (libecap)	ELSA-2020-4743	2020-11-10
Oracle Linux version 8 (squid)	ELSA-2020-4743	2020-11-10

This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team