NULL pointer dereference in Squid Software Foundation The Squid Software Foundation Squid
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
This vulnerability allows remote attackers to deny service on vulnerable installations of The Squid Software Foundation Squid 3.5.27-20180318. Authentication is not required to exploit this vulnerability. The specific flaw exists within ClientRequestContext::sslBumpAccessCheck(). A crafted request can trigger the dereference of a null pointer. An attacker can leverage this vulnerability to create a denial-of-service condition to users of the system. Was ZDI-CAN-6088.
Why it matters now
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 |
|---|---|---|---|---|---|
| The Squid Software Foundation | The Squid Software Foundation Squid | 3.5.27-20180318 | — | No fix listed | CNA |
- The Squid Software Foundation Squid VendorThe Squid Software Foundation Affected 3.5.27-20180318 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:squid-cache:squid:3.5.27:*:*:*:*:*:*:* | 3.5.27 | Vulnerable | squid-cache |
- cpe:2.3:a:squid-cache:squid:3.5.27:*:*:*:*:*:*:* Versions 3.5.27 Vulnerable ·squid-cache
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. 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 yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2018-1172
- 2026-10-03 Alias added: GHSA-5pj9-pxj3-pc8r
References
More squid-cache Squid vulnerabilities
- TI-2025-38486 Squid vulnerable to information disclosure via authentication credential leakage in error handling CVSS 3.1CRITICAL 10.0
- TI-2024-16845 Denial of Service in HTTP Header parser in squid proxy CVSS 3.1HIGH 7.5
- TI-2024-16566 SQUID-2024:1 Denial of Service in HTTP Chunked Decoding CVSS 3.1HIGH 8.6
- TI-2023-26921 Denial of Service in HTTP Message Processing in Squid CVSS 3.1HIGH 8.6
- TI-2023-27496 SQUID-2023:10 Denial of Service in HTTP Request parsing CVSS 3.1HIGH 8.6
- TI-2023-25306 Squid: denial of service in http digest authentication CVSS 3.1HIGH 8.6
Sources
- CVE-2018-1172 · CVE Program
- CVE-2018-1172 · NVD
- FIRST EPSS
- GHSA-5pj9-pxj3-pc8r · GitHub Advisory Database · CC BY 4.0
- CVE-2018-1172 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences