CVE-2023-27537: Use After Free
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.
Other sources
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.
— MITRE
cURL libcurl is vulnerable to a denial of service, caused by a double free or use-after-free flaw when sharing HSTS data between separate "handles". By sending a specially crafted request, a remote attacker could exploit this vulnerability to cause a denial of service condition.
— IBM
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID of this vulnerability?
The vulnerability ID of this vulnerability is CVE-2023-27537.
What is the severity rating of CVE-2023-27537?
The severity rating of CVE-2023-27537 is medium.
What is affected by CVE-2023-27537?
Libcurl versions 7.88.0 and 7.88.1 are affected by CVE-2023-27537.
How can I mitigate CVE-2023-27537?
To mitigate CVE-2023-27537, it is recommended to update libcurl to version 8.0.0 or later.
Where can I find more information about CVE-2023-27537?
You can find more information about CVE-2023-27537 in the following references: [HackerOne report](https://hackerone.com/reports/1897203), [Gentoo security advisory](https://security.gentoo.org/glsa/202310-12), [NetApp advisory](https://security.netapp.com/advisory/ntap-20230420-0010/).