__________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2019:5 __________________________________________________________________ Advisory ID: SQUID-2019:5 Date: July 12, 2019 Summary: Heap Overflow issue in HTTP Basic Authentication processing. Affected versions: Squid 4.0.23 -> 4.7 Fixed in version: Squid 4.8 __________________________________________________________________ http://www.squid-cache.org/Advisories/SQUID-2019_5.txt http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12527 __________________________________________________________________ Problem Description: Due to incorrect buffer management Squid is vulnerable to a heap overflow and possible remote code execution attack when processing HTTP Authentication credentials. __________________________________________________________________ Severity: This allows a malicious client to write a substantial amount of arbitrary data to the heap. Potentially gaining ability to execute arbitrary code. On systems with memory access protections this can result in the Squid process being terminated unexpectedly. Resulting in a denial of service for all clients using the proxy. This issue is limited to traffic accessing the Squid Cache Manager reports or using the FTP protocol gateway. __________________________________________________________________ Updated Packages: 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: Squid 4: 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-2.x are not vulnerable. All Squid-3.x are not vulnerable. All Squid-4.x up to and including 4.0.22 are not vulnerable. All Squid-4.0.23 up to and including 4.7 built with Basic Authentication features are vulnerable. __________________________________________________________________ Workarounds: Either; Deny ftp:// protocol URLs being proxied and Cache Manager report access to all clients: acl FTP proto FTP http_access deny FTP http_access deny manager Or, Build Squid with --disable-auth-basic __________________________________________________________________ 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 your 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 . 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@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 Jeriko One . Fixed by Amos Jeffries of Treehouse Networks Ltd. __________________________________________________________________ Revision history: 2019-05-14 14:56:49 UTC Initial Report 2019-06-05 15:52:17 UTC CVE Assignment 2019-06-19 05:58:36 UTC Patches Released 2019-07-12 13:00:00 UTC Advisory Released __________________________________________________________________ END