CVE-2024-23638
SQUID-2023:11 Denial of Service in Cache Manager
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Description
Squid is a caching proxy for the Web. Due to an expired pointer reference bug, Squid prior to version 6.6 is vulnerable to a Denial of Service attack against Cache Manager error responses. This problem allows a trusted client to perform Denial of Service when generating error pages for Client Manager reports. Squid older than 5.0.5 have not been tested and should be assumed to be vulnerable. All Squid-5.x up to and including 5.9 are vulnerable. All Squid-6.x up to and including 6.5 are vulnerable. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives. As a workaround, prevent access to Cache Manager using Squid's main access control: `http_access deny manager`.
Official description from the CVE record, published by GitHub_M. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS 3.1 Medium 6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: Low
A basic user account is needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: High
Serious or total effect on availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. |
| Privileges required | Low | A basic user account is needed. |
| User interaction | None | No action from any user is needed. |
| Scope | Unchanged | The impact stays within the vulnerable component. |
| Confidentiality impact | None | No effect on the secrecy of data. |
| Integrity impact | None | No effect on the trustworthiness of data. |
| Availability impact | High | Serious or total effect on availability. |
CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.
EPSS
- Score
- 0.60050 (60.1% probability)
- Percentile
- 99.1%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
CISA assessment as of Jan 24, 2024
- Exploitation
- Public proof of concept recorded by CISA
- Automatable
- no
- Technical impact
- partial
Weakness (CWE)
- CWE-825Expired Pointer Dereference
Affected products
squid-cache squid
- affected: < 6.6
References
- github.com/squid-cache/squid/security/advisories/GHSA-j49p-…
- github.com/squid-cache/squid/commit/290ae202883ac28a4886707…
- github.com/squid-cache/squid/commit/e8118a7381213f5cfcdeb4c…
- megamansec.github.io/Squid-Security-Audit/stream-assert.html
- squid-cache.org/Versions/v5/SQUID-2023_11.patch
- squid-cache.org/Versions/v6/SQUID-2023_11.patch
- security.netapp.com/advisory/ntap-20240208-0010
- lists.fedoraproject.org/archives/list/package-announce@list…
- lists.fedoraproject.org/archives/list/package-announce@list…
Timeline
- ID reserved
- Record published
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:51 UTC. Sources and licenses