CVE-2019-12521
5.9 · MEDIUMOverview
CVE-2019-12521 is a medium-severity vulnerability affecting squid-cache squid. It was published on April 15, 2020 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.
Remediation
Check the references section for vendor advisories and patches from squid-cache. Update squid to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| squid-cache | squid | 3.0 | Affected |
References
Frequently Asked Questions
What is CVE-2019-12521?
CVE-2019-12521 is a medium-severity vulnerability affecting squid-cache squid. It was published on April 15, 2020 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
How severe is CVE-2019-12521?
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2019-12521?
Check the references section for vendor advisories and patches from squid-cache. Update squid to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2019-12521?
CyberStrike's AI-powered security agents can automatically detect CVE-2019-12521 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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