CVE-2019-12521

Public on 2020-06-01
Modified on 2020-06-03
Description
A flaw was found in squid. 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.
Severity
Medium
CVSS v3 Base Score
5.9
See breakdown

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 1 squid 2020-06-01 12:25 ALAS-2020-1378

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD CVSSv2 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P
NVD CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H