CVE-2023-46724Network attack vector

Proxy crash via wildcard certificate buffer under-read

Published Nov 1, 2023 · Updated Feb 13, 2025

Out-of-bounds read in Squid 3.3.0.1 through 6.3 allows remote attackers to crash the proxy via a crafted TLS certificate chain. The matchDomainName function decrements and dereferences an empty certificate-domain length after check_domain strips a lone wildcard common name. Exposure requires an OpenSSL-enabled build processing HTTPS or SSL-Bump traffic; the invalid read can terminate the proxy service.

CVSS severity8.6
High
EPSS probability4.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Squid 3.3.0.1 through 6.3 allows remote attackers to crash the proxy via a crafted TLS certificate chain. The matchDomainName function decrements and dereferences an empty certificate-domain length after check_domain strips a lone wildcard common name. Exposure requires an OpenSSL-enabled build processing HTTPS or SSL-Bump traffic; the invalid read can terminate the proxy service.

The record

CVE
CVE-2023-46724
Published
Nov 1, 2023
Updated
Feb 13, 2025
Vendor
The Squid Software Foundation
Product
Squid
Classifications
CWE-1285, CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 3.3.0.1, < 6.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Squid Software Foundation · Squidversion=>= 3.3.0.1, < 6.4

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.6GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1285Improper Validation of Specified Index, Position, or Offset in Input
CWE-125Out-of-bounds Read
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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