Squid: dos against http and https
Priority LOW 39CWE-755Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 12 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
A flaw was found in Squid. The limits applied for validation of HTTP response headers are applied before caching. However, Squid may grow a cached HTTP response header beyond the configured maximum size, causing a stall or crash of the worker process when a large header is retrieved from the disk cache, resulting in a denial of service.
Why it matters now
EPSS 0.03284 88th percentileScored 2026-11-07
Fix Partial Red Hat: 8 advisoriesRed Hat: 12 fixed, 2 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 8 | — | 8090020231130092412.a75119d5 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.2 Advanced Update Support | — | 8020020240122164331.4cda2c84 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.2 Telecommunications Update Service | — | 8020020240122164331.4cda2c84 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions | — | 8020020240122164331.4cda2c84 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | — | 8040020240122165847.522a0ee4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Telecommunications Update Service | — | 8040020240122165847.522a0ee4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions | — | 8040020240122165847.522a0ee4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support | — | 8060020231222131040.ad008a3a | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8.8 Extended Update Support | — | 8080020231222130009.63b34585 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 7:5.5-6.el9_3.2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.0 Extended Update Support | — | 7:5.2-1.el9_0.4 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9.2 Extended Update Support | — | 7:5.5-5.el9_2.3 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 8090020231130092412.a75119d5 Patch available CNA
- Red Hat Enterprise Linux 8.2 Advanced Update Support VendorRed Hat Affected — Fixed in 8020020240122164331.4cda2c84 Patch available CNA
- Red Hat Enterprise Linux 8.2 Telecommunications Update Service VendorRed Hat Affected — Fixed in 8020020240122164331.4cda2c84 Patch available CNA
- Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 8020020240122164331.4cda2c84 Patch available CNA
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support VendorRed Hat Affected — Fixed in 8040020240122165847.522a0ee4 Patch available CNA
- Red Hat Enterprise Linux 8.4 Telecommunications Update Service VendorRed Hat Affected — Fixed in 8040020240122165847.522a0ee4 Patch available CNA
- Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions VendorRed Hat Affected — Fixed in 8040020240122165847.522a0ee4 Patch available CNA
- Red Hat Enterprise Linux 8.6 Extended Update Support VendorRed Hat Affected — Fixed in 8060020231222131040.ad008a3a Patch available CNA
- Red Hat Enterprise Linux 8.8 Extended Update Support VendorRed Hat Affected — Fixed in 8080020231222130009.63b34585 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 7:5.5-6.el9_3.2 Patch available CNA
- Red Hat Enterprise Linux 9.0 Extended Update Support VendorRed Hat Affected — Fixed in 7:5.2-1.el9_0.4 Patch available CNA
- Red Hat Enterprise Linux 9.2 Extended Update Support VendorRed Hat Affected — Fixed in 7:5.5-5.el9_2.3 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* | before 6.4 | Vulnerable | squid-cache |
| cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* | 6.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
- cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* Versions before 6.4 Vulnerable ·squid-cache
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
Remediation
Red Hat 8 advisories
- RHSA-2024:1153 Released 2024-03-05 · Red Hat rating Importantsquid security update
- Red Hat Enterprise Linux AppStream EUS (v.9.0) squid-7:5.2-1.el9_0.4
- RHSA-2024:0771 Released 2024-02-12 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream EUS (v.8.6) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.aarch64::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.s390x::squid:4 +11
- RHSA-2024:0773 Released 2024-02-12 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
- Red Hat Enterprise Linux AppStream E4S (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +5
- Red Hat Enterprise Linux AppStream TUS (v.8.4) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
Show 5 more Red Hat advisories
- RHSA-2024:0772 Released 2024-02-12 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream AUS (v. 8.2) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
- Red Hat Enterprise Linux AppStream E4S (v. 8.2) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +5
- Red Hat Enterprise Linux AppStream TUS (v. 8.2) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.src::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4, libecap-devel-1.0.1-2.module+el8.1.0+4044+36416a77.x86_64::squid:4 +2
- RHSA-2024:0397 Released 2024-01-24 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream EUS (v.8.8) libecap-1.0.1-2.module+el8.1.0+4044+36416a77.aarch64::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le::squid:4, libecap-1.0.1-2.module+el8.1.0+4044+36416a77.s390x::squid:4 +11
- RHSA-2024:0072 Released 2024-01-08 · Red Hat rating Importantsquid security update
- Red Hat Enterprise Linux AppStream EUS (v.9.2) squid-7:5.5-5.el9_2.3
- RHSA-2023:7668 Released 2023-12-06 · Red Hat rating Importantsquid:4 security update
- Red Hat Enterprise Linux AppStream (v. 8) libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.aarch64::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.ppc64le::squid:4, libecap-1.0.1-2.module+el8.9.0+19703+a1da7223.s390x::squid:4 +11
- RHSA-2023:7465 Released 2023-11-22 · Red Hat rating Importantsquid security update
- Red Hat Enterprise Linux AppStream (v. 9) squid-7:5.5-6.el9_3.2
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2023:7668 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2023:7465 |
| Red Hat Enterprise Linux AppStream AUS (v. 8.2) | Fixed | RHSA-2024:0772 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2024:0773 |
| Red Hat Enterprise Linux AppStream E4S (v. 8.2) | Fixed | RHSA-2024:0772 |
| Red Hat Enterprise Linux AppStream E4S (v.8.4) | Fixed | RHSA-2024:0773 |
| Red Hat Enterprise Linux AppStream EUS (v.8.6) | Fixed | RHSA-2024:0771 |
| Red Hat Enterprise Linux AppStream EUS (v.8.8) | Fixed | RHSA-2024:0397 |
| Red Hat Enterprise Linux AppStream EUS (v.9.0) | Fixed | RHSA-2024:1153 |
| Red Hat Enterprise Linux AppStream EUS (v.9.2) | Fixed | RHSA-2024:0072 |
| Red Hat Enterprise Linux AppStream TUS (v. 8.2) | Fixed | RHSA-2024:0772 |
| Red Hat Enterprise Linux AppStream TUS (v.8.4) | Fixed | RHSA-2024:0773 |
Timeline
- 2026-10-02 Threatist record created from CVE-2023-5824
- 2026-10-19 EPSS moved to the 50th–90th percentile
- 2026-10-19 Priority changed: MEDIUM → LOW
References
More Red Hat Enterprise Linux vulnerabilities
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2018-10530 Code injection in [UNKNOWN] RichFaces KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2023-5824 · CVE Program
- CVE-2023-5824 · NVD
- FIRST EPSS
- CVE-2023-5824 · Red Hat security data · CC BY 4.0
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