CVE-2019-12521 Information
Share on:Description
An issue was discovered in Squid through 4.7. When Squid is parsing ESI it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed it is added via addStackElement. addStackElement has a check for the number of elements in this buffer but it’s off by 1 leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can’t affect adjacent memory blocks and thus just leads to a crash while processing.
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Reference
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00018.html http://www.openwall.com/lists/oss-security/2020/04/23/1 https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12521.txt https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html https://security.gentoo.org/glsa/202005-05 https://usn.ubuntu.com/4356-1/ https://www.debian.org/security/2020/dsa-4682
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction Required
NONE
Scope
NONE
Confidentiality Impact
UNCHANGED
Integrity Impact
NONE
Availability Impact
NONE
Base Score
HIGH
Base Severity
5.9