{"id":"CVE-2023-5824","title":"Squid: dos against http and https","summary":"A flaw was found in Squid. The limits applied for validation of HTTP response headers are applied before caching. However, Squid may grow a cached HTTP response header beyond the configured maximum size, causing a stall or crash of the w…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-755"],"vendor":"Red Hat","product":"squid:4","affected":["squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid:4 (all versions)","squid (all versions)","squid (all versions)","squid (all versions)","squid (all versions)","squid (all versions)"],"published":"2023-11-03","updated":"2026-11-04","sourceUpdated":"2026-11-04T21:06:17.325Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-5824","references":[{"url":"https://access.redhat.com/errata/RHSA-2023:7465","label":"RHSA-2023:7465"},{"url":"https://access.redhat.com/errata/RHSA-2023:7668","label":"RHSA-2023:7668"},{"url":"https://access.redhat.com/errata/RHSA-2024:0072","label":"RHSA-2024:0072"},{"url":"https://access.redhat.com/errata/RHSA-2024:0397","label":"RHSA-2024:0397"},{"url":"https://access.redhat.com/errata/RHSA-2024:0771","label":"RHSA-2024:0771"},{"url":"https://access.redhat.com/errata/RHSA-2024:0772","label":"RHSA-2024:0772"},{"url":"https://access.redhat.com/errata/RHSA-2024:0773","label":"RHSA-2024:0773"},{"url":"https://access.redhat.com/errata/RHSA-2024:1153","label":"RHSA-2024:1153"},{"url":"https://access.redhat.com/security/cve/CVE-2023-5824"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2245914","label":"RHBZ#2245914"},{"url":"https://github.com/squid-cache/squid/security/advisories/GHSA-543m-w2m2-g255"}],"tags":["cve.org"],"epss":0.03284,"epssPercentile":0.88498,"ingestedAt":"2026-11-05T21:36:00.592Z","slug":"CVE-2023-5824","body":"## Overview\n\nA flaw was found in Squid. The limits applied for validation of HTTP response headers are applied before caching. However, Squid may grow a cached HTTP response header beyond the configured maximum size, causing a stall or crash of the worker process when a large header is retrieved from the disk cache, resulting in a denial of service.\n\n## Affected\n\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid:4 (all versions)`\n- `squid (all versions)`\n- `squid (all versions)`\n- `squid (all versions)`\n- `squid (all versions)`\n- `squid (all versions)`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nDisabling the disk caching mechanism will mitigate this vulnerability. To achieve this, remove all the 'cache_dir' directives from the Squid configuration, typically in the /etc/squid/squid.conf file.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":41.3,"likelihood":0.7,"exploitation":0,"ransomware":0},"changes":[]}