CVE-2021-22947: Medium severity Apple macOS Monterey vulnerability
A flaw was found in curl. The flaw lies in how curl handles cached or pipelined responses that it receives from either a IMAP, POP3, SMTP or FTP server before the TLS upgrade using STARTTLS. In such a scenario curl even after upgrading to TLS would trust these cached responses treating them as valid and authenticated and use them. An attacker could potentially use this flaw to carry out a Man-In-The-Middle attack. The highest threat from this vulnerability is to data confidentiality.
Other sources
curl. Multiple issues were addressed by updating to curl version 7.79.1.
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 attacker's injected data comes from the TLS-protected server.
When curl connects to an IMAP, POP3, SMTP or FTP server to exchange data securely using STARTTLS to upgrade the connection to TLS level, the server can still respond and send back multiple responses before the TLS upgrade. 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 attacker's injected data comes from the TLS-protected server.
Upstream Advisory:
https://github.com/curl/curl/commit/ec3bb8f727405
— Red Hat
Credit
Affected Software
Remediation
Patch Available
Patch Available
Patch Available
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2022-22633
- CVE-2022-22669
- CVE-2022-22665
- CVE-2022-22630
- CVE-2022-22631
- CVE-2022-22625
- CVE-2022-22648
- CVE-2022-22626
- CVE-2022-22627
- CVE-2022-22597
- CVE-2022-22616
- CVE-2022-22663
- CVE-2022-26691
- CVE-2021-22946
- CVE-2021-22947
- CVE-2021-22945
- CVE-2022-22643
- CVE-2022-22657
- CVE-2022-22664
- CVE-2021-30977
- CVE-2022-22611
- CVE-2022-22612
- CVE-2022-46706
- CVE-2022-22661
- CVE-2022-22641
- CVE-2022-22613
- CVE-2022-22614
- CVE-2022-22615
- CVE-2022-22632
- CVE-2022-22638
- CVE-2022-22640
- CVE-2021-30946
- CVE-2021-36976
- CVE-2022-21658
- CVE-2022-22647
- CVE-2022-22656
- CVE-2022-22672
- CVE-2022-22644
- CVE-2022-26690
- CVE-2022-26688
- CVE-2022-22617
- CVE-2022-22609
- CVE-2022-22650
- CVE-2022-22655
- CVE-2022-22600
- CVE-2022-22599
- CVE-2022-22651
- CVE-2022-22639
- CVE-2022-22660
- CVE-2022-22621
- CVE-2021-4136
- CVE-2021-4166
- CVE-2021-4173
- CVE-2021-4187
- CVE-2021-4192
- CVE-2021-4193
- CVE-2021-46059
- CVE-2022-0128
- CVE-2022-0156
- CVE-2022-0158
- CVE-2021-30918
- CVE-2022-22662
- CVE-2022-22610
- CVE-2022-22624
- CVE-2022-22628
- CVE-2022-22629
- CVE-2022-22637
- CVE-2022-22668
- CVE-2022-22582
Frequently Asked Questions
What is CVE-2021-22947?
CVE-2021-22947 is a vulnerability in the curl software library that allows a server to send multiple responses at once, leading to potential security issues.
What is the severity of CVE-2021-22947?
The severity of CVE-2021-22947 is medium, with a CVSS score of 6.1.
How does CVE-2021-22947 affect the curl software?
CVE-2021-22947 affects curl versions 7.20.0 to 7.78.0 when using STARTTLS to upgrade to TLS security for IMAP or POP3 connections.
How can I fix CVE-2021-22947?
To fix CVE-2021-22947, update to curl version 7.79.1 or higher.
Where can I find more information about CVE-2021-22947?
You can find more information about CVE-2021-22947 at the following references: [link1], [link2], [link3].