Multiple vulnerabilities cURL libcurl affect AIX

IBM SECURITY ADVISORY

First Issued: Thu Jun 29 09:35:59 CDT 2023

The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/curl_advisory2.asc

Security Bulletin: Multiple vulnerabilities cURL libcurl affect AIX

===============================================================================

SUMMARY:

Multiple vulnerabilities in cURL libcurl affect AIX. AIX uses cURL libcurl 
as part of LV/PV encryption integration with HPCS.

===============================================================================

VULNERABILITY DETAILS:

CVEID: CVE-2022-43552
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID: CVE-2022-43551
    https://vulners.com/cve/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 Environmental Score*: Undefined
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
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID: CVE-2023-27538
    https://vulners.com/cve/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: 4.0
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/250533
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N)

CVEID: CVE-2023-27534
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID: CVE-2023-27535
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID: CVE-2023-27533
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N)

CVEID: CVE-2023-27536
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID: CVE-2022-27782
    https://vulners.com/cve/CVE-2022-27782
DESCRIPTION: cURL libcurl could allow a remote attacker to bypass security
    restrictions, caused by an easy connection reuse flaw for TLS and SSH.
    By sending a specially-crafted request using the connections in a
    connection pool, an attacker could exploit this vulnerability to
    bypass access restrictions.
CVSS Base Score: 9.8
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/226252
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID: CVE-2023-23916
    https://vulners.com/cve/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 Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID: CVE-2022-32206
    https://vulners.com/cve/CVE-2022-32206
DESCRIPTION: cURL libcurl is vulnerable to a denial of service, caused by
    a flaw in the number of acceptable "links" in the "chained" HTTP
    compression algorithms. By persuading a victim to connect a
    specially-crafted server, a remote attacker could exploit this
    vulnerability to insert a virtually unlimited number of compression
    steps, and results in a denial of service condition.
CVSS Base Score: 4.3
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/229740
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 7.3 TL1

    The following fileset levels are vulnerable:
    
    key_fileset = aix

    Fileset                 Lower Level  Upper Level KEY 
    ---------------------------------------------------------
    oss.lib.libcurl         7.79.1.0     7.79.1.0    key_w_fs
    
    Note: This bulletin does not apply to versions of curl installed from
    the AIX Toolbox.

    To find out whether the affected filesets are installed 
    on your systems, refer to the lslpp command found in AIX user's guide.

    Example:  lslpp -L | grep -i oss.lib.libcurl


REMEDIATION:

    A. FIXES

        IBM strongly recommends addressing the vulnerability now.

        AIX fixes are available. The fixes are cumulative and address
        previously issued AIX cURL libcurl security bulletins:
        https://aix.software.ibm.com/aix/efixes/security/curl_advisory.asc
        https://www.ibm.com/support/pages/node/6998763

        The AIX fixes can be downloaded via https from:
        https://aix.software.ibm.com/aix/efixes/security/curl_fix2.tar 

        The link above is to a tar file containing this signed
        advisory, fix packages, and OpenSSL signatures for each package.
        The fixes below include prerequisite checking. This will
        enforce the correct mapping between the fixes and AIX
        Technology Levels.

        AIX Level  Interim Fix (*.Z)        KEY
        ---------------------------------------------
        7.3.1      curl7791a.230622.epkg.Z  key_w_fix

        Please reference the Affected Products and Version section above
        for help with checking installed fileset levels.

        To extract the fixes from the tar file:

        tar xvf curl_fix2.tar
        cd curl_fix2

        Verify you have retrieved the fixes intact:

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

        openssl dgst -sha256                                              filename                 KEY
        -----------------------------------------------------------------------------------------------------
        dfbb25813981c786a10f28a6d896d8b405f4d7c6301afcd928ae953cef133465  curl7791a.230622.epkg.Z  key_w_csum

        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 at
        http://ibm.com/support/ and describe the discrepancy.         

        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/security/curl_advisory2.asc.sig

    B. FIX AND INTERIM FIX INSTALLATION

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

        To preview a fix installation:

        installp -a -d fix_name -p all  # where fix_name is the name of the
                                        # fix package being previewed.
        To install a fix package:

        installp -a -d fix_name -X all  # where fix_name is the name of the
                                        # fix package being installed.

        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.

        To preview an interim fix installation:

        emgr -e ipkg_name -p         # where ipkg_name is the name of the
                                     # interim fix package being previewed.

        To install an interim fix package:

        emgr -e ipkg_name -X         # where ipkg_name is the name of the
                                     # interim fix package being installed.

WORKAROUNDS AND MITIGATIONS:

    None.

===============================================================================

CONTACT US:

Note: Keywords labeled as KEY in this document are used for parsing
purposes.

If you would like to receive AIX Security Advisories via email,
please visit "My Notifications":

    http://www.ibm.com/support/mynotifications

Contact IBM Support for questions related to this announcement:

    https://ibm.com/support/

For information on how to securely verify AIX security bulletins and fixes:

    https://www.ibm.com/support/pages/node/6985269

To obtain the OpenSSL public key that can be used to verify the
signed advisories and ifixes:

    Download the key from our web page:

ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt
https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt

To verify the AIX/VIOS security bulletin:

    Published advisory OpenSSL signature file location:

    https://aix.software.ibm.com/aix/efixes/security/curl_advisory2.asc.sig

    openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]

Please contact your local IBM AIX support center for any
assistance.

REFERENCES:

Complete CVSS v3 Guide:  http://www.first.org/cvss/user-guide
On-line Calculator v3:
    http://www.first.org/cvss/calculator/3.0

RELATED INFORMATION:

IBM Secure Engineering Web Portal
    http://www.ibm.com/security/secure-engineering/bulletins.html

IBM Product Security Incident Response Blog
    https://www.ibm.com/blogs/psirt/

Security Bulletin: Multiple vulnerabilities cURL libcurl affect AIX
    https://www.ibm.com/support/pages/node/7008409

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Thu Jun 29 09:35:59 CDT 2023

===============================================================================

*The CVSS Environment Score is customer environment specific and will
ultimately impact the Overall CVSS Score. Customers can evaluate the impact
of this vulnerability in their environments by accessing the links in the
Reference section of this Security Bulletin.

Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the
Common Vulnerability Scoring System (CVSS) is an “industry open standard
designed to convey vulnerability severity and help to determine urgency and
priority of response.” IBM PROVIDES THE CVSS SCORES “AS IS” WITHOUT WARRANTY
OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT
OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.