CVE-2023-5824

Squid: dos against http and https

HIGH
7.5
CVSS Score
Published: November 3, 2023 at 07:56 AM UTC
Updated: June 17, 2026 at 06:49 AM UTC
3 products affected across 2 vendorsEnterprise LinuxSquidCache Squid

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Severity
HIGH7.5
Exploit prediction
EPSS 3%

Description

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 worker process when a large header is retrieved from the disk cache, resulting in a denial of service.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 7:5.2-1.el9_0.4 (unaffected)
Vendor states this is fixed in 7:5.5-5.el9_2.3 (unaffected)
Vendor states this is fixed in 7:5.5-6.el9_3.2 (unaffected)
Vendor states this is fixed in 8020020240122164331.4cda2c84 (unaffected)
Vendor states this is fixed in 8040020240122165847.522a0ee4 (unaffected)
Vendor states this is fixed in 8060020231222131040.ad008a3a (unaffected)
Vendor states this is fixed in 8080020231222130009.63b34585 (unaffected)
Vendor states this is fixed in 8090020231130092412.a75119d5 (unaffected)
v < 6.4
Affected range stops below 6.4, so it looks safe — our inference, not a vendor statement
v < 6.4
Affected range stops below 6.4, so it looks safe — our inference, not a vendor statement

References (13)

CVSS

7.5HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-755

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