CVE ID:	CVE-2019-12519
Description:	An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow.
Test IDs:	None available
Cross References:	Common Vulnerability Exposure (CVE) ID: CVE-2019-12519 Debian Security Information: DSA-4682 (Google Search) https://www.debian.org/security/2020/dsa-4682 https://security.gentoo.org/glsa/202005-05 https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12519.txt https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html http://www.openwall.com/lists/oss-security/2020/04/23/1 SuSE Security Announcement: openSUSE-SU-2020:0623 (Google Search) http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html https://usn.ubuntu.com/4356-1/