CVE-2021-22901
curl: Use-after-free in TLS session handling when using OpenSSL TLS backend
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 26, 2021
Updated · October 9, 2026
Description
A use-after-free flaw was found in the way curl handled TLS session data. The curl versions using the OpenSSL library as their TLS backend could use freed memory after TLS session renegotiation was performed by the OpenSSL library. A malicious TLS server could use this flaw to crash or, possibly, execute arbitrary code with the privileges of a client application using the curl library.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE-416 · Use After Free