CVE-2023-46728Network attack vector

Proxy crash via Gopher response NULL dereference

Published Nov 6, 2023 · Updated Nov 3, 2025

NULL pointer dereference in the Gopher gateway in Squid before 6.0.1 allows remote attackers to crash the proxy via a Gopher response. The gateway processes a response received from any Gopher server and dereferences a NULL pointer, terminating Squid's single proxy process. Gopher support is always enabled in affected releases, so a client able to make the proxy fetch a Gopher URL can interrupt service for all proxy users.

CVSS severity7.5
High
EPSS probability5.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Gopher gateway in Squid before 6.0.1 allows remote attackers to crash the proxy via a Gopher response. The gateway processes a response received from any Gopher server and dereferences a NULL pointer, terminating Squid's single proxy process. Gopher support is always enabled in affected releases, so a client able to make the proxy fetch a Gopher URL can interrupt service for all proxy users.

The record

CVE
CVE-2023-46728
Published
Nov 6, 2023
Updated
Nov 3, 2025
Vendor
The Squid Software Foundation
Product
Squid
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Squid Software Foundation · Squidversion=< 6.0.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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