NetSight
medium5.9

CVE-2019-12521

An issue was discovered in Squid through 4.7.

Impact

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 products

VendorProductAffected versions
Squid-CacheSquid
from 3.0 through 3.5.28
from 4.0 through 4.7
from 5.0 through 5.0.1
CanonicalUbuntu Linux
Versions 16.04, 18.04, 19.10, 20.04
DebianDebian Linux
Versions 9.0, 10.0
OpensuseLeap
Version 15.1

Weakness classification

References