Bug 1827570 (CVE-2019-12524)

Summary: CVE-2019-12524 squid: Improper access restriction in url_regex may lead to security bypass
Product: [Other] Security Response Reporter: Marian Rehak <mrehak>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anon.amish, ccheney, code, jonathansteffan, luhliari, uwe.knop
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: squid 4.8 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in squid. The Cache Manager for Squid has rules that, by default, block access to anyone other than the maintainer. An attacker, with the ability to send a properly crafted URL, can bypass the url_regex check and gain access to the blocked resource. The highest threat from this vulnerability is to data confidentiality.
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-11-04 02:25:07 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1828371, 1828375    
Bug Blocks: 1827553    

Description Marian Rehak 2020-04-24 08:45:33 UTC
Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.

Comment 3 Stefan Cornelius 2020-04-24 13:50:47 UTC
External References:


Comment 6 Product Security DevOps Team 2020-11-04 02:25:07 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):


Comment 7 errata-xmlrpc 2020-11-04 03:32:02 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4743 https://access.redhat.com/errata/RHSA-2020:4743