Bug 1730528 (CVE-2019-12529)

Summary:	CVE-2019-12529 squid: Out of bounds read in Proxy-Authorization header causes DoS
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	anon.amish, code, jonathansteffan, kyoshida, luhliari, uwe.knop, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	squid 4.8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-04 02:21:34 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1730529, 1738580, 1738581
Bug Blocks:	1730537

Description Dhananjay Arunesh 2019-07-17 04:14:59 UTC

An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode. uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The length is then used to start decoding the string. There are no checks to ensure that the length it calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the display of usernames on error pages.

Reference:
http://www.squid-cache.org/Versions/v4/changesets/
https://github.com/squid-cache/squid/commits/v4

Upstream commit:
http://www.squid-cache.org/Versions/v4/changesets/squid-4-dd46b5417809647f561d8a5e0e74c3aacd235258.patch

Comment 1 Dhananjay Arunesh 2019-07-17 04:15:59 UTC

Created squid tracking bugs for this issue:

Affects: fedora-all [bug 1730529]

Comment 2 Cedric Buissart 2019-08-07 10:08:32 UTC

External References:

http://www.squid-cache.org/Advisories/SQUID-2019_2.txt

Comment 3 Cedric Buissart 2019-08-07 13:48:56 UTC

Mitigation:

Remove 'auth_param basic ...' configuration settings from squid.conf

Comment 6 Product Security DevOps Team 2020-11-04 02:21:34 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2019-12529

Comment 7 errata-xmlrpc 2020-11-04 03:31:12 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