CVE-2021-28651

HIGH
7.5
CVSS Score
Published: May 27, 2021 at 12:00 AM UTC
Updated: June 17, 2026 at 03:46 AM UTC
4 products affected across 4 vendorsDebian LinuxFedoraCache Squid

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Severity
HIGH7.5
Exploit prediction
EPSS 7%

Description

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.

Affected

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

All versions
2.0 ≤ v < 4.155.0 ≤ v < 5.0.6
Affected range stops below 4.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.0.6, so it looks safe — our inference, not a vendor statement

CVSS

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

Quick Info

StatusMODIFIED
CWE
CWE-401

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