Security Bulletin: Multiple vulnerabilities in Curl affect PowerSC

Summary

There are multiple vulnerabilities in Curl that affect PowerSC.

Vulnerability Details

CVEID:CVE-2023-27534
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a SFTP path ~ resolving discrepancy flaw. By sending a specially crafted request using a tilde (~) character, an attacker could exploit this vulnerability to obtain sensitive information from other directory, 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/250529 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-2022-43552
**DESCRIPTION:**cURL libcurl is vulnerable to a denial of service, caused by a use-after-free flaw when using an HTTP proxy. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 5.9
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/242799 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2023-23914
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a flaw in the HSTS function when multiple URLs are requested serially. By sniffing the network traffic, an attacker could exploit this vulnerability to obtain sensitive information, 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/247433 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-2023-23916
**DESCRIPTION:**cURL libcurl is vulnerable to a denial of service, caused by a flaw in the decompression chain implementation. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause memory errors, and results in a denial of service condition.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/247437 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-2023-27533
**DESCRIPTION:**cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a TELNET option IAC injection flaw. By sending a specially crafted request, an attacker could exploit this vulnerability to pass on user name and “telnet options” for the server negotiation.
CVSS Base score: 8.2
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/250476 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N)

CVEID:CVE-2023-23915
**DESCRIPTION:**cURL libcurl could allow a remote attacker to obtain sensitive information, caused by a flaw in the HSTS function when multiple URLs are requested in parallel. By sniffing the network traffic, an attacker could exploit this vulnerability to obtain sensitive information, 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/247436 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-2023-27536
**DESCRIPTION:**cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a GSS delegation too eager connection re-use flaw. By sending a specially crafted request, an attacker could exploit this vulnerability to reuse a previously created connection even when the GSS delegation.
CVSS Base score: 5.9
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/250531 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID:CVE-2022-43551
**DESCRIPTION:**cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a flaw when the host name in the given URL first uses IDN characters that get replaced to ASCII counterparts as part of the IDN conversion. By sending a specially-crafted request, an attacker could exploit this vulnerability to bypass HSTS check.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/242798 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)

CVEID:CVE-2023-27537
**DESCRIPTION:**cURL libcurl is vulnerable to a denial of service, caused by a double free or use-after-free flaw when sharing HSTS data between separate “handles”. By sending a specially crafted request, 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/250532 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-2023-27535
**DESCRIPTION:**cURL libcurl could allow a remote attacker to bypass security restrictions, caused by a FTP too eager connection reuse flaw. By sending a specially crafted request, an attacker could exploit this vulnerability to reuse a previously created FTP connection.
CVSS Base score: 5.9
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/250530 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID:CVE-2023-27538
**DESCRIPTION:**cURL libcurl could allow a local attacker to bypass security restrictions, caused by a SSH connection too eager reuse still flaw. By sending a specially crafted request, an attacker could exploit this vulnerability to reuse a previously created connection even when an SSH related option had been changed.
CVSS Base score: 4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/250533 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/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

IBM strongly recommends addressing the vulnerability now.

Fixes are available.

The fixes can be downloaded via ftp or http from:

<https://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix11.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_fix11.tar

cd curl_fix11

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.

To verify the security bulletin and fix:

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:

<https://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory11.asc.sig&gt;

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_fix11.tar

cd curl_fix11

To install a fix package:

rpm -ivh *.rpm

rpm -Uvh *.rpm

To install any dependencies along with the fix package:

yum update curl

Workarounds and Mitigations

None