CVE-2019-12521
MEDIUM5.9EPSS 0.56%Published: 4/15/2020Modified: 11/19/2025
Also known as:ALPINE-CVE-2019-12521DEBIAN-CVE-2019-12521
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.
Affected packages (2)
- Alpine/squidfrom 0, < 4.11-r0
- Debian/squidfrom 0, < 4.11-1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |