IBM SECURITY ADVISORY First Issued: Mon Jul 12 14:18:52 CDT 2021 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc https://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc ftp://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc Security Bulletin: Vulnerabilities in Curl affect PowerSC (CVE-2021-22876 and CVE-2021-22890) =============================================================================== SUMMARY: There are vulnerabilities in Curl that affect PowerSC. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2021-22876 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22876 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22876 DESCRIPTION: cURL libcurl could allow a remote attacker to obtain sensitive information, caused by the failure to strip off user credentials from the URL when automatically populating the Referer: HTTP request header field in outgoing HTTP requests. By sending a specially-crafted HTTP request, 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: 7.5 CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/199186 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-2021-22890 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22890 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22890 DESCRIPTION: cURL libcurl is vulnerable to a man-in-the-middle attack, caused by a session tickets confusing issue when using a HTTPS proxy and TLS 1.3. 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: 5.9 CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/199188 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) AFFECTED PRODUCTS AND VERSIONS: PowerSC 1.2 PowerSC 1.3 The vulnerabilities in the following filesets are being addressed: key_fileset = powerscStd.tnc_pm key_fileset = curl-7.74.0-1.aix6.1.ppc.rpm Fileset Lower Level Upper Level KEY --------------------------------------------------------------- powerscStd.tnc_pm 1.2.0.3 1.3.0.5 key_w_fs curl-7.76.1-1.aix6.1.ppc.rpm 7.19.4 7.76.0 key_w_fs 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: 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_fix6.tar http://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix6.tar https://aix.software.ibm.com/aix/efixes/powersc/security/curl_fix6.tar 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_fix6.tar cd curl_fix6 Verify you have retrieved the fixes intact: The checksums below were generated using the "openssl dgst -sha256 " command as the following: openssl dgst -sha256 filename KEY ------------------------------------------------------------------------------------------------------------------------ 95ae1e55a1bd3d6311bd20363c3b596003391dd2902b99c4e58fa40226c3d0af curl-7.76.1-1.aix6.1.ppc.rpm key_w_csum 08ddc62bc54d7e7ac7e7cd5b1f79dddca7c559f0b7c8c63a7685404236a264ca ca-certificates-2020.06.01-2.aix6.1.ppc.rpm key_w_csum f79ef9e87fadb23574ce4da53aa79bdf45668e138d9da3975ff22aef511c265e krb5-libs-1.18.3-1.aix6.1.ppc.rpm key_w_csum 5c107b7919f89bfc9f76dd2bd4fe15e650c8ed303010ea094b1f799bfdae605c openldap-2.4.58-1.aix6.1.ppc.rpm 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. openssl dgst -sha256 -verify -signature .sig openssl dgst -sha256 -verify -signature .sig Published advisory OpenSSL signature file location: http://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc.sig https://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc.sig ftp://aix.software.ibm.com/aix/efixes/powersc/security/curl_advisory6.asc.sig 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_fix6.tar cd curl_fix6 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. =============================================================================== CONTACT US: Note: Keywords labeled as KEY in this document are used for parsing purposes. If you would like to receive PowerSC Security Advisories via email, please visit "My Notifications": http://www.ibm.com/support/mynotifications https://www.ibm.com/support/mynotifications To view previously issued advisories, please visit: http://www14.software.ibm.com/webapp/set2/subscriptions/onvdq https://www14.software.ibm.com/webapp/set2/subscriptions/onvdq Contact IBM Support for questions related to this announcement: http://ibm.com/support/ https://ibm.com/support/ 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 Please contact your local IBM AIX support center for any assistance. REFERENCES: Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide https://www.first.org/cvss/user-guide On-line Calculator v3: http://www.first.org/cvss/calculator/3.0 https://www.first.org/cvss/calculator/3.0 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Mon Jul 12 14:18:52 CDT 2021 =============================================================================== *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.