CVE Vulnerabilities

CVE-2021-22947

Insufficient Verification of Data Authenticity

Published: Sep 29, 2021 | Modified: Nov 07, 2023
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/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

When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches. curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got before the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attackers injected data comes from the TLS-protected server.

Weakness

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

Affected Software

Name Vendor Start Version End Version
Curl Haxx 7.20.0 *

References