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AUSCERT External Security Bulletin Redistribution
ESB-2020.2886
SQUID - Multiple advisories
24 August 2020
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: SQUID
Publisher: SQUID
Operating System: Windows
UNIX variants (UNIX, Linux, OSX)
Impact/Access: Denial of Service -- Remote/Unauthenticated
Provide Misleading Information -- Existing Account
Access Confidential Data -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2020-15811 CVE-2020-15810
Original Bulletin:
https://github.com/squid-cache/squid/security/advisories/GHSA-c7p8-xqhm-49wv
https://github.com/squid-cache/squid/security/advisories/GHSA-vvj7-xjgq-g2jg
https://github.com/squid-cache/squid/security/advisories/GHSA-3365-q9qx-f98m
Comment: This bulletin contains three (3) SQUID security advisories.
- --------------------------BEGIN INCLUDED TEXT--------------------
SQUID-2020:8 HTTP(S) Request Splitting
yadij published GHSA-c7p8-xqhm-49wv Aug 23, 2020
Severity
critical
Affected versions
2.7-3.5.28, 4.0-4.12, 5.0.1-5.0.3
Patched versions
4.13, 5.0.4
CVE identifier
CVE-2020-15811
Problem Description:
Due to incorrect data validation Squid is vulnerable to HTTP Request Splitting
attacks against HTTP and HTTPS traffic. This leads to cache poisoning.
- -------------------------------------------------------------------------------
Severity:
This problem is serious because it 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.
CVSS Score of 9.3
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:L/UI:N
/S:C/C:H/I:H/A:N/E:F/RL:O/RC:C/CR:H/IR:H/AR:X/MAV:N/MAC:L/MPR:L/MUI:N/MS:C/MC:H
/MI:H/MA:N&version=3.1
- -------------------------------------------------------------------------------
Updated Packages:
This bug is fixed by Squid versions 4.13 and 5.0.4.
In addition, patches addressing this problem for the stable
releases can be found in our patch archives:
Squid 4:
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_8.patch
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
packages.
- -------------------------------------------------------------------------------
Determining if your version is vulnerable:
All Squid configured with "relaxed_header_parser off" are not vulnerable.
All Squid-3.x up to and including 3.5.28 with relaxed_header_parser configured
to
"on" or "warn" are vulnerable.
All Squid-3.x up to and including 3.5.28 without relaxed_header_parser
configured
are vulnerable.
All Squid-4.x up to and including 4.12 with relaxed_header_parser configured to
"on" or "warn" are vulnerable.
All Squid-4.x up to and including 4.12 without relaxed_header_parser configured
are vulnerable.
All Squid-5.x up to and including 5.0.3 with relaxed_header_parser configured
to
"on" or "warn" are vulnerable.
All Squid-5.x up to and including 5.0.3 without relaxed_header_parser
configured
are vulnerable.
- -------------------------------------------------------------------------------
Workaround:
Disable the relaxed HTTP parser in squid.conf:
relaxed_header_parser off
Note, traffic which does not correctly obey HTTP specifications
will be rejected instead of converted to standards compliance.
- -------------------------------------------------------------------------------
Contact details for the Squid project:
For installation / upgrade support on binary packaged versions
of Squid: Your first point of contact should be your binary
package vendor.
If you install and build Squid from the original Squid sources
then the squid-users@lists.squid-cache.org mailing list is your
primary support point. For subscription details see
http://www.squid-cache.org/Support/mailing-lists.html.
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
http://bugs.squid-cache.org/.
For reporting of security sensitive bugs send an email to the
squid-bugs@lists.squid-cache.org mailing list. It's a closed
list (though anyone can post) and security related bug reports
are treated in confidence until the impact has been established.
- -------------------------------------------------------------------------------
Credits:
This vulnerability was discovered by Regis Leroy (regilero
from Makina Corpus).
Fixed by Amos Jeffries of Treehouse Networks Ltd.
- -------------------------------------------------------------------------------
Revision history:
2019-07-24 11:52:51 UTC Initial Report
2020-01-09 22:07:44 UTC Additional vectors discovered
- --------------------------------------------------------------------------------
SQUID-2020:9 Denial of Service processing Cache Digest Response
yadij published GHSA-vvj7-xjgq-g2jg Aug 23, 2020
Severity
critical
Affected versions
3.0-4.12, 5.0.1-5.0.3
Patched versions
4.13, 5.0.4
Problem Description:
Due to Improper Input Validation Squid is vulnerable to a Denial of Service
attack
against the machine operating Squid.
- -------------------------------------------------------------------------------
Severity:
This problem allows a trusted peer to deliver to perform Denial of Service by
consuming all available CPU cycles on the machine running Squid when handling
a crafted Cache Digest response message.
This attack is limited to Squid using cache_peer with cache digests feature.
CVSS Score of 9.5
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:N
/S:C/C:N/I:N/A:H/E:H/RL:O/RC:C/CR:X/IR:X/AR:H/MAV:N/MAC:L/MPR:X/MUI:N/MS:C/MC:N
/MI:N/MA:H&version=3.1
- -------------------------------------------------------------------------------
Updated Packages:
This bug is fixed by Squid versions 4.13 and 5.0.4.
In addition, patches addressing this problem for the stable
releases can be found in our patch archives:
Squid 4:
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_9.patch
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
packages.
- -------------------------------------------------------------------------------
Determining if your version is vulnerable:
All Squid built using --disable-cache-digests are not vulnerable.
All Squid without cache_peer directives configured are not vulnerable.
All Squid-3.x up to and including 3.5.28 using cache_peer directives with
no-digest
option configured are not vulnerable.
All Squid-3.x up to and including 3.5.28 using cache_peer directives without
the
no-digest option configured are vulnerable.
All Squid-4.x up to and including 4.12 using cache_peer directives with
no-digest
option configured are not vulnerable.
All Squid-4.x up to and including 4.12 using cache_peer directives without the
no-digest option configured are vulnerable.
All Squid-5.x up to and including 5.0.3 using cache_peer directives with
no-digest
option configured are not vulnerable.
All Squid-5.x up to and including 5.0.3 using cache_peer directives without the
no-digest option configured are vulnerable.
- -------------------------------------------------------------------------------
Workaround:
Either,
Add the no-digest option to all cache_peer lines in squid.conf
Or,
Build Squid with --disable-cache-digests
- -------------------------------------------------------------------------------
Contact details for the Squid project:
For installation / upgrade support on binary packaged versions
of Squid: Your first point of contact should be your binary
package vendor.
If you install and build Squid from the original Squid sources
then the squid-users@lists.squid-cache.org mailing list is your
primary support point. For subscription details see
http://www.squid-cache.org/Support/mailing-lists.html.
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
http://bugs.squid-cache.org/.
For reporting of security sensitive bugs send an email to the
squid-bugs@lists.squid-cache.org mailing list. It's a closed
list (though anyone can post) and security related bug reports
are treated in confidence until the impact has been established.
- -------------------------------------------------------------------------------
Credits:
This vulnerability was discovered by Lubos Uhliarik of RedHat.
Fixed by Eduard Bagdasaryan (The Measurement Factory).
- -------------------------------------------------------------------------------
Revision history:
2019-09-30 17:12:18 UTC Initial Report
2020-07-29 20:51:58 UTC Fix committed
- --------------------------------------------------------------------------------
SQUID-2020:10 HTTP(S) Request Smuggling
yadij published GHSA-3365-q9qx-f98m Aug 23, 2020
Severity
critical
Affected versions
2.5-3.5.28, 4.0-4.12, 5.0.1-5.0.3
Patched versions
4.13, 5.0.4
CVE identifier
CVE-2020-15810
Problem Description:
Due to incorrect data validation Squid is vulnerable to HTTP Request Smuggling
attacks against HTTP and HTTPS traffic. This leads to cache poisoning.
- -------------------------------------------------------------------------------
Severity:
This problem is serious because it allows any client, including
browser scripts, to bypass local security and poison the proxy
cache and any downstream caches with content from an arbitrary
source.
CVSS Score of 9.3
https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:L/UI:N
/S:C/C:H/I:H/A:N/E:F/RL:O/RC:C/CR:H/IR:H/AR:X/MAV:N/MAC:L/MPR:L/MUI:N/MS:C/MC:H
/MI:H/MA:N&version=3.1
- -------------------------------------------------------------------------------
Updated Packages:
This bug is fixed by Squid versions 4.13 and 5.0.4.
In addition, patches addressing this problem for the stable
releases can be found in our patch archives:
Squid 4:
http://www.squid-cache.org/Versions/v4/changesets/SQUID-2020_10.patch
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
packages.
- -------------------------------------------------------------------------------
Determining if your version is vulnerable:
All Squid with relaxed_header_parser configured "off" are not vulnerable.
All Squid-3.x up to and including 3.5.28 with relaxed_header_parser configured
to
"on" or "warn" are vulnerable.
All Squid-3.x up to and including 3.5.28 without relaxed_header_parser
configured
are vulnerable.
All Squid-4.x up to and including 4.12 with relaxed_header_parser configured to
"on" or "warn" are vulnerable.
All Squid-4.x up to and including 4.12 without relaxed_header_parser configured
are vulnerable.
All Squid-5.x up to and including 5.0.3 with relaxed_header_parser configured
to
"on" or "warn" are vulnerable.
All Squid-5.x up to and including 5.0.3 without relaxed_header_parser
configured
are vulnerable.
- -------------------------------------------------------------------------------
Workaround:
Disable the relaxed HTTP parser in squid.conf:
relaxed_header_parser off
Note, traffic which does not correctly obey HTTP specifications
will be rejected instead of converted to standards compliance.
- -------------------------------------------------------------------------------
Contact details for the Squid project:
For installation / upgrade support on binary packaged versions
of Squid: Your first point of contact should be your binary
package vendor.
If you install and build Squid from the original Squid sources
then the squid-users@lists.squid-cache.org mailing list is your
primary support point. For subscription details see
http://www.squid-cache.org/Support/mailing-lists.html.
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
http://bugs.squid-cache.org/.
For reporting of security sensitive bugs send an email to the
squid-bugs@lists.squid-cache.org mailing list. It's a closed
list (though anyone can post) and security related bug reports
are treated in confidence until the impact has been established.
- -------------------------------------------------------------------------------
Credits:
This vulnerability was discovered by Amit Klein of Safebreach.
Fixed by Amos Jeffries of Treehouse Networks Ltd.
- -------------------------------------------------------------------------------
Revision history:
2020-05-11 08:21:58 UTC Initial Report
2020-07-17 17:11:50 UTC CVE Allocated
- --------------------------END INCLUDED TEXT--------------------
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