CVE Vulnerabilities

CVE-2021-22890

Authentication Bypass by Spoofing

Published: Apr 01, 2021 | Modified: Nov 07, 2023
CVSS 3.x
3.7
LOW
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly short-cut the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.

Weakness

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Affected Software

Name Vendor Start Version End Version
Libcurl Haxx 7.63.0 7.75.0

References