CVE-2019-12523
CRITICALCVSS 9.1/10EPSS 4.30%
Last modified
CVE-2019-12523 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is made. EPSS estimates a 4.30% chance of exploitation in the next 30 days.
Description
An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker can connect to HTTP servers that only listen on localhost.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Squid-Cache | Squid | >= 3.0, <= 3.5.28 |
| Squid-Cache | Squid | >= 4.0, <= 4.8 |
| Canonical | Ubuntu Linux | 16.04 |
| Canonical | Ubuntu Linux | 18.04 |
| Canonical | Ubuntu Linux | 19.04 |
| Canonical | Ubuntu Linux | 19.10 |
| Fedoraproject | Fedora | 30 |
| Fedoraproject | Fedora | 31 |
| Opensuse | Leap | 15.0 |
| Debian | Debian Linux | 9.0 |
| Debian | Debian Linux | 10.0 |
References
- http://www.squid-cache.org/Advisories/SQUID-2019_8.txtThird Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1156329Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.htmlMailing List, Third Party Advisory
- https://usn.ubuntu.com/4213-1/Third Party Advisory
- https://usn.ubuntu.com/4446-1/Third Party Advisory
- https://www.debian.org/security/2020/dsa-4682Third Party Advisory
- http://www.squid-cache.org/Advisories/SQUID-2019_8.txtThird Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1156329Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/07/msg00009.htmlMailing List, Third Party Advisory
- https://usn.ubuntu.com/4213-1/Third Party Advisory
- https://usn.ubuntu.com/4446-1/Third Party Advisory
- https://www.debian.org/security/2020/dsa-4682Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2019-12523?
An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker can connect to HTTP servers that only listen on localhost.
How severe is CVE-2019-12523?
CVE-2019-12523 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 4.30% probability of exploitation in the next 30 days.
How do I fix CVE-2019-12523?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2019-12523?
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