CVE-2019-12521 - CVE House
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Status published Medium CVE-2019-12521

An issue was discovered in Squid through 4.7. When Squid...

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

squid-cache

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Affected Software

squid, ubuntu linux, debian linux, leap
Vulnerable Versions:
3.0, 4.0, 5.0, 16.04, 18.04, 19.10, 20.04, 9.0, 10.0, 15.1

Timeline

Official Publish: April 15th, 2020
Last Modified: August 4th, 2024
Added to House: July 20th, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.