CVE-2024-25617

Denial of Service in HTTP Header parser in squid proxy

HIGH
7.5
CVSS Score
Published: February 14, 2024 at 08:55 PM UTC
Updated: June 17, 2026 at 07:16 AM UTC
3 products affected across 2 vendorsSquidBluexpCache Squid

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Severity
HIGH7.5
Exploit prediction
EPSS 88%
SSVC
No known exploit

Description

Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Collapse of Data into Unsafe Value bug ,Squid may be vulnerable to a Denial of Service attack against HTTP header parsing. This problem allows a remote client or a remote server to perform Denial of Service when sending oversized headers in HTTP messages. In versions of Squid prior to 6.5 this can be achieved if the request_header_max_size or reply_header_max_size settings are unchanged from the default. In Squid version 6.5 and later, the default setting of these parameters is safe. Squid will emit a critical warning in cache.log if the administrator is setting these parameters to unsafe values. Squid will not at this time prevent these settings from being changed to unsafe values. Users are advised to upgrade to version 6.5. There are no known workarounds for this vulnerability. This issue is also tracked as SQUID-2024:2

Affected

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

All versions
v < 6.53.0 ≤ v < 6.5
Affected range stops below 6.5, so it looks safe — our inference, not a vendor statement
v < 6.53.0 ≤ v < 6.5
Affected range stops below 6.5, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

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

Quick Info

StatusANALYZED
CWE
CWE-182CWE-400NVD-CWE-Other

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