CVE-2021-22947: Medium severity Apple macOS Monterey vulnerability

Published Sep 10, 2021
·
Updated

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

CVE-2021-22946, CVE-2021-22947, CVE-2021-22945

Affected Software

68 affected componentsFixes available
redhat/rh-dotnet31-curl<0:7.61.1-22.el7_9
0:7.61.1-22.el7_9
redhat/curl<0:7.61.1-18.el8_4.2
0:7.61.1-18.el8_4.2
redhat/curl<0:7.61.1-12.el8_2.4
0:7.61.1-12.el8_2.4
debian/curl<=7.64.0-4+deb10u2
7.64.0-4+deb10u77.74.0-1.3+deb11u97.74.0-1.3+deb11u107.88.1-10+deb12u37.88.1-10+deb12u48.4.0-2
redhat/curl<7.79.0
7.79.0
Apple macOS Monterey<12.3
12.3
haxx curl>=7.20.0<7.79.0
Fedoraproject Fedora=33
Fedoraproject Fedora=35
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Debian Debian Linux=11.0
NetApp Cloud Backup
NetApp Clustered Data ONTAP
All of the following
NetApp H300s Firmware
NetApp H300s
All of the following
NetApp H500s Firmware
NetApp H500s
All of the following
NetApp H700s Firmware
NetApp H700s
All of the following
NetApp H300e Firmware
NetApp H300e
All of the following
NetApp H500e Firmware
NetApp H500e
All of the following
NetApp H700e Firmware
NetApp H700e
All of the following
NetApp H410s Firmware
NetApp H410s
All of the following
NetApp Solidfire Baseboard Management Controller Firmware
NetApp Solidfire Baseboard Management Controller
Oracle Communications Cloud Native Core Binding Support Function=1.11.0
Oracle Communications Cloud Native Core Network Function Cloud Native Environment=1.10.0
Oracle Communications Cloud Native Core Network Repository Function=1.15.0
Oracle Communications Cloud Native Core Network Repository Function=1.15.1
Oracle Communications Cloud Native Core Network Slice Selection Function=1.8.0
Oracle Communications Cloud Native Core Service Communication Proxy=1.15.0
Oracle MySQL Server>=5.7.0<=5.7.35
Oracle MySQL Server>=8.0.0<=8.0.26
Oracle PeopleSoft Enterprise PeopleTools=8.57
Oracle PeopleSoft Enterprise PeopleTools=8.58
Oracle PeopleSoft Enterprise PeopleTools=8.59
Siemens Sinec Infrastructure Network Services<1.0.1.1
Apple macOS<12.3
Oracle Commerce Guided Search=11.3.2
Oracle Communications Cloud Native Core Binding Support Function=22.1.3
Oracle Communications Cloud Native Core Console=22.2.0
Oracle Communications Cloud Native Core Network Repository Function=22.1.2
Oracle Communications Cloud Native Core Network Repository Function=22.2.0
Oracle Communications Cloud Native Core Security Edge Protection Proxy=22.1.1
Splunk Universal Forwarder>=8.2.0<8.2.12
Splunk Universal Forwarder>=9.0.0<9.0.6
Splunk Universal Forwarder=9.1.0
NetApp H300s Firmware
NetApp H300s
NetApp H500s Firmware
NetApp H500s
NetApp H700s Firmware
NetApp H700s
NetApp H300e Firmware
NetApp H300e
NetApp H500e Firmware
NetApp H500e
NetApp H700e Firmware
NetApp H700e
NetApp H410s Firmware
NetApp H410s
NetApp Solidfire Baseboard Management Controller Firmware
NetApp Solidfire Baseboard Management Controller

Event History

Sep 15, 2021
CVE Published
12:00 AM
Sep 29, 2021
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
DescriptionWeakness
Data Sourced
via NVD·08:15 PM
RemedyDescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

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.

2

What is the severity of CVE-2021-22947?

The severity of CVE-2021-22947 is medium, with a CVSS score of 6.1.

3

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.

4

How can I fix CVE-2021-22947?

To fix CVE-2021-22947, update to curl version 7.79.1 or higher.

5

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].

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