CVE-2019-12521 — Off-by-one Error in Squid
Severity
5.9MEDIUMNVD
OSV9.8
EPSS
0.6%
top 31.53%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedApr 15
Latest updateMay 24
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 pr…
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 2.2 | Impact: 3.6
Affected Packages4 packages
Also affects: Debian Linux 10.0, 9.0, Ubuntu Linux 16.04, 18.04, 19.10, 20.04
Patches
🔴Vulnerability Details
4📋Vendor Advisories
3💬Community
1Bugzilla▶
CVE-2019-12521 squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash↗2020-04-24