__________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2020:10 __________________________________________________________________
Advisory ID: | SQUID-2020:10 Date: | August 1, 2020 Summary: | HTTP(S) Request Smuggling. Affected versions: | Squid 2.5 -> 2.7.STABLE9 | Squid 3.x -> 3.5.28 | Squid 4.x -> 4.12 | Squid 5.x -> 5.0.3 Fixed in version: | Squid 4.13, 5.0.4 __________________________________________________________________ <http://cve.mitre.org/cgi-bin/cvename.cgi?name=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-us...@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-b...@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 _______________________________________________ squid-announce mailing list squid-announce@lists.squid-cache.org http://lists.squid-cache.org/listinfo/squid-announce