What’s Vulnerable › Vulnerabilities

CVE-2023-27537

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-03-30 · updated 2026-10-23
• Weakness: CWE-415

Description

A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double-free or use-after-free.

Affected products

• Broadcom Brocade Fabric Operating System Firmware: all versions
• curl: 7.88.0, 7.88.1
• Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
• Clustered Data ONTAP: 9.0
• NetApp H300S Firmware: all versions
• NetApp H410S Firmware: all versions
• NetApp H500S Firmware: all versions
• NetApp H700S Firmware: all versions
• Splunk Universal Forwarder: from 8.2.0 before 8.2.12; from 9.0.0 before 9.0.6; 9.1.0 — fixed in 8.2.12, 9.0.6

How to fix

Upgrade to a fixed version: Splunk Universal Forwarder 8.2.12, 9.0.6. Check the vendor advisory for mitigations.

References

• https://hackerone.com/reports/1897203
• https://security.gentoo.org/glsa/202310-12
• https://security.netapp.com/advisory/ntap-20230420-0010/
• https://hackerone.com/reports/1897203
• https://security.gentoo.org/glsa/202310-12
• https://security.netapp.com/advisory/ntap-20230420-0010/
• https://cert-portal.siemens.com/productcert/html/ssa-398330.html
• https://cert-portal.siemens.com/productcert/html/ssa-943925.html

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