[squid-announce] [ADVISORY] SQUID-2019:1 Denial of Service issue in cachemgr.cgi
squid3 at treenet.co.nz
Sat Jul 13 13:31:10 UTC 2019
Squid Proxy Cache Security Update Advisory SQUID-2019:1
Advisory ID: SQUID-2019:1
Date: July 12, 2019
Summary: Denial of Service issue
Affected versions: Squid 4.x -> 4.7
Fixed in version: Squid 4.8
Due to incorrect string termination the cachemgr.cgi may access
On systems with memory access protections this can result in
the CGI process terminating unexpectedly. Resulting in a
denial of service for all clients using it.
This problem allows a remote attacker with access to the Squid
manager API to perform a denial of service on other clients.
This problem is limited to the cachemgr CGI binary.
Web servers which run per-client instances of CGI tools are
affected by the issue, but the denial of service is not able to
affect other clients.
This bug is fixed by Squid version 4.8.
In addition, patches addressing this problem for the stable
releases can be found in our patch archives:
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
Determining if your version is vulnerable:
All cachemgr.cgi 3.x and older versions are not vulnerable.
All cachemgr.cgi 4.x versions up to and including 4.7 are
All Squid-4.7 and older versions accessed via the http:// URL
manager interface are not vulnerable.
To determine the version and interface, look at the footer of
manager reports for the "Generated by" string.
Convert to exclusively using the HTTP manager interface until
cachemgr.cgi can be upgraded to a fixed build.
Deny all access with 'manager' ACL in squid.conf.
This completely removes the vulnerability at cost of reduced
management and monitoring capabilities.
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
If your install and build Squid from the original Squid sources
then the squid-users at lists.squid-cache.org mailing list is your
primary support point. For subscription details see
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
For reporting of security sensitive bugs send an email to the
squid-bugs at 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.
This vulnerability was discovered by Alex Rousskov of The
Fixed by Amos Jeffries from Treehouse Networks Ltd.
2019-04-10 21:13:50 UTC Initial Report
2019-05-18 09:43:41 UTC Patch Released
2019-06-16 10:52:51 UTC CVE Assignment
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