Security Bulletin: Multiple vulnerabilities in Curl affect PowerSC

Summary

There are multiple vulnerabilities in Curl that affect PowerSC.

Vulnerability Details

CVEID:CVE-2021-22897
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. An attacker could exploit this vulnerability to expose data element to wrong session.
CVSS Base score: 3.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/203609 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N)

CVEID:CVE-2021-22922
**DESCRIPTION:**cURL libcurl could allow a remote attacker to bypass security restrictions, caused by not removing incorrect content by the metalink feature. By persuading a victim to download specially-crafted content, an attacker could exploit this vulnerability to access malicious content to keep in the file on disk for further attack.
CVSS Base score: 7.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/206045 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-22901
**DESCRIPTION:**cURL libcurl could allow a remote attacker to execute arbitrary code on the system, caused by a flaw when a new TLS session is negotiated or a client certificate is requested on an existing connection. By persuading a victim to visit a specially-crafted Web site, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.8
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/202563 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

CVEID:CVE-2021-22898
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a flaw in the option parser for sending NEW_ENV variables. By sending a specially-crafted request using a clear-text network protocol, an attacker could exploit this vulnerability to obtain sensitive internal information to the server, and use this information to launch further attacks against the affected system.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/202562 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID:CVE-2021-22945
**DESCRIPTION:**cURL libcurl is vulnerable to a denial of service, caused by a use-after-free and double free flaw when sending data to an MQTT server. By sending a specially-crafted data, a remote attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/209451 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2021-22924
**DESCRIPTION:**An unspecified error with bad connection reused due to improper path name validation in cURL libcurl has an unknown impact and attack vector.
CVSS Base score: 5.3
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/206047 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)

CVEID:CVE-2021-22925
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a flaw in the option parser for sending NEW_ENV variables. By sniffing the network traffic, an attacker could exploit this vulnerability to obtain TELNET stack contents, and use this information to launch further attacks against the affected system.
CVSS Base score: 6.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/206051 for the current score.
CVSS Vector: (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID:CVE-2021-22923
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by improper protection to user credentials by the metalink feature. By persuading a victim to connect a specially-crafted server, an attacker could exploit this vulnerability to obtain user credentials, and use this information to launch further attacks against the affected system.
CVSS Base score: 6.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/206046 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N)

CVEID:CVE-2021-22947
**DESCRIPTION:**cURL libcurl is vulnerable to a man-in-the-middle attack, caused by a flaw when connecting to an IMAP, POP3, SMTP or FTP server to exchange data securely using STARTTLS to upgrade the connection to TLS level. An attacker could exploit this vulnerability to launch a man-in-the-middle attack and gain access to the communication channel between endpoints to obtain sensitive information or further compromise the system.
CVSS Base score: 7.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/209453 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)

CVEID:CVE-2021-22946
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a required TLS bypassed issue. By sniffing the network, an attacker could exploit this vulnerability to obtain sensitive data in clear text over the network, and use this information to launch further attacks against the affected system.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/209452 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

The vulnerabilities in the following filesets are being addressed:

Note: To find out whether the affected PowerSC filesets are installed on your systems, refer to the lslpp command found in AIX user’s guide. To find out whether the affected curl filesets are installed on your systems, refer to the rpm command found in AIX user’s guide.

Example: lslpp -l | grep powerscStd

Example: rpm -qa | grep curl

Remediation/Fixes

A. FIXES

Fixes are available.

The fixes can be downloaded via ftp or http from:

<ftp://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix7.tar&gt;

<http://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix7.tar&gt;

<https://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix7.tar&gt;

The link above is to a tar file containing this signed advisory, open source fix packages, and OpenSSL signatures for each package.

To extract the fixes from the tar file:

tar xvf curl_fix7.tar

cd curl_fix7

Verify you have retrieved the fixes intact:

The checksums below were generated using the “openssl dgst -sha256 [filename]” command as the following:

These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM Support.

openssl dgst -sha256 -verify <pubkey_file> -signature <advisory_file>.sig <advisory_file>

openssl dgst -sha256 -verify <pubkey_file> -signature <ifix_file>.sig <ifix_file>

Published advisory OpenSSL signature file location:

<http://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory7.asc.sig&gt;

<https://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory7.asc.sig&gt;

ftp://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory7.a…

B. FIX AND INTERIM FIX INSTALLATION

IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding.

To extract the fixes from the tar file:

tar xvf curl_fix7.tar

cd curl_fix7

To install a fix package:

rpm -ivh *.rpm

rpm -Uvh *.rpm

Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them.

Workarounds and Mitigations

None